Secretion of reproductive hormones and estrous cycle in rats interfered by combined exposure to beta-cypermethrin and emamectin benzoate / 环境与职业医学

Backgroud Beta-cypermethrin and emamectin benzoate are widely used for the prevention and control of pests in the greenhouse planting industry, and their combined exposure may increase the accumulation of beta-cypermethrin and emamectin benzoate in organisms and affect human health. Objective Based on the changes in reproductive hormone levels in the hypothalamic-pituitary-ovarian (HPO) axis, to investigate the effect of combined exposure to beta-cypermethrin and emamectin benzoate on the estrous cycle of female mice. Methods Twenty-four healthy adult SD rats were randomly divided into a blank control group, a beta-cypermethrin group (Beta-CYP, 53 mg·m−3), an emamectin benzoate group (EMB, 8 mg·m−3), and a beta-cypermethrin and emamectin benzoate combined exposure group (Beta-CYP+EMB, Beta-CYP 53 mg·m−3 + EMB 8 mg·m−3). Six rats in each group were exposed to the designed treatment protocol by aerosol inhalation 6 d a week for 13 weeks. The general condition of the rats was observed in real time during the treatment. From the 12th week of exposure, a 10-day reproductive tract smear was performed on the rats to observe the estrous cycle. The rats were neutralized on the second day after the end of the treatment protocol, and the ovarian tissues were stained with HE to observe histopathological changes. Serum levels of gonadotropin-releasing hormone (GnRH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E2) were measured by ELISA. Experimental results were expressed as mean ± standard deviation (\begin{document}$ \overline{x}\pm s $\end{document}). One-way ANOVA was used for comparison among groups, and LSD test for pairwise comparison between groups. The significance level was α=0.05. Results After four weeks of the treatment protocol, the rats in the Beta-CYP group and the Beta-CYP+EMB group continued to be hyperactive and irritable, while the EMB group showed symptoms of mental disorder, decreased activity, and slow response. On the 90th day of the treatment protocol, the body weight of rats in the control group increased to (314.51±2.44) g, and that in the Beta-CYP+EMB group only increased to (253.47±1.50) g. There was no abnormal cellular morphology in the control group; however, small deeply stained nuclei appeared in the Beta-CYP group, the EMB group, and the Beta-CYP+EMB group, and abnormal morphological development of keratinized epithelial cells in the Beta-CYP+EMB group was found. The estrous cycle of rats in the control group was (97.83±4.17) h, and compared with the control group, the estrous cycles of rats in the Beta-CYP group, the EMB group, and the Beta-CYP+EMB group were prolonged to (134.33±7.53) h, (126.50±5.28) h, and (156.00±6.66) h, respectively. The results of ANOVA showed that the numbers of leukocytes (527.17±15.83), keratinized epithelial cells (35.67±4.32), and non-keratinized epithelial cells (70.50±4.51) in the vaginal smears during diestrus in the Beta-CYP+EMB group were significantly lower than those in the control group (752.50±28.89, 50.50±2.74, 101.33±7.92) (P<0.001). The hormone levels of GnRH and FSH in the control group were (5.13±0.59) and (0.76±0.09) IU·L−1 respectively, while the levels in the Beta-CYP+EMB group were increased to (16.86±0.59) and (3.80±0.19) IU·L−1 respectively (P<0.05). The levels of LH and E2 in the control group were (12.93±0.81) IU·L−1 and (22.23±1.44) pmol·L−1 respectively, and the levels in the Beta-CYP+EMB group were decreased to (5.63±0.41) IU·L−1 and (10.45±0.78) pmol·L−1 respectively (P<0.05). Conclusion The combined exposure to beta-cypermethrin and emamectin benzoate may ultimately affect the estrous cycle of female rats by interfering with the secretion of reproductive hormones involved in the HPO axis.

An Experimental Study- to Evaluate the Effect of Shatapushpa Taila on Estrous Phase of Female Wistar Albino Rats

From early adolescence to menopause, the menstrual cycle affects a woman’s physiological and psychological health for about 35 to 40 years in a normal population. Properly functioning hypothalamo pituitary ovarian axis, receptive endometrium with healthy ovum and sperm are considered to be the essential factors for conception. Acharyas have quoted Rutu, Kshetra, Ambhu and Beeja as Garbha sambhava samagri which is essential for conception where in Beeja can be taken as ovum. Shatapusha is mentioned in Kashyapa samhitha as Artavajanaka, hence an effort to evaluate its effect on estrous phase of female Wistar albino rats is the aim of this study. The selected animal was grouped into four groups with 6 animals each. The animal experiment showed significant increase in estrus phase of the oestrous cycle in rats which is the active phase of mating where the female receives the male.

Reproductive and fertility parameters of ewes from the Colombian tropical highlands / Parámetros reproductivos y de fertilidad de ovejas en el trópico alto de Colombia

ABSTRACT Two studies were conducted on sheep in the high tropics of Colombia to study reproductive and fertility parameters associated with animal growth in this ecological zone. In the first trial, 1,389 records were used to analyze, through descriptive statistics, the fertility parameters, the birth rate, and the yield per multiple births of three genetic groups of sheep: the native Criolla and Manchada Paramuna breeds, and they were compared with the imported race Blackface. In the second study, the duration of the estrous cycle was determined and serum progesterone values were determined during the estrous cycle in 19 Criolla x Romney Marsh crossbred ewes, in this experiment, five moments of the cycle were analyzed. The fertility rates found in the Criolla and Manchada Paramuna breeds were 73.1 and 72 %, respectively, and were higher than those of the Blackface sheep (65 %). Blackface ewes showed the highest incidence of multiple births (29 %) and Manchada Paramuna ewes had the highest birth rates (93.7 %). Criolla x Romney Marsh crossbred ewes recorded a mean duration of the estrous cycle of 17.8 d. The highest progesterone secretion (11.5 nmol/L) occurred on day 9 of the estrous cycle, while in the estrus phases, its value was 0.32 nmol/L. This study contributes to the knowledge of the reproductive aspects of Colombian native sheep.

RESUMEN Se realizaron dos estudios en ovejas en el trópico alto de Colombia, para estudiar los parámetros reproductivos y de fertilidad asociados con el crecimiento animal, en esta zona ecológica. En el primer ensayo, se utilizaron 1.389 registros para analizar, a través de estadísticas descriptivas, los parámetros de fertilidad, la tasa de natalidad y el rendimiento por parto múltiple, de tres grupos genéticos de ovejas: las razas nativas Criolla y Manchada Paramuna y se compararon con la raza importada Blackface. En el segundo estudio, se determinó la duración del ciclo estral y se determinaron valores de progesterona sérica durante el ciclo estral, en 19 ovejas cruzadas Criolla x Romney Marsh; en este experimento, se analizaron cinco momentos del ciclo. Las tasas de fertilidad encontradas en las razas Criolla y Manchada Paramuna fue de 73,1 y 72 %, respectivamente, superior a la de las ovejas Blackface (65 %). Las ovejas Blackface mostraron la mayor incidencia de partos múltiples (29 %) y las ovejas Manchada Paramuna tuvieron las tasas de parto más altas (93,7 %). Las ovejas cruzadas Criolla x Romney Marsh registraron una duración media del ciclo estral de 17,8 d. La mayor secreción de progesterona (11,5 nmol/L) ocurrió el día 9 del ciclo estral, mientras que en las fases del estro, su valor fue de 0,32 nmol/L. Este estudio contribuye con el conocimiento de los aspectos reproductivos de las ovejas nativas colombianas.

Retirada de corpo estranho (dispositivo impregnado com progesterona) da cavidade abdominal de novilha da raça Jersey ­ relato de caso / Removal of a foreign body (progesterone impregnated device) from the abdominal cavity of a Jersey heifer ­ a case report / Extracción de cuerpo extraño (dispositivo impregnado con progesterona) de la cavidad abdominal de novilla raza Jersey - reporte de caso

A inseminação artificial em tempo fixo (IATF) é uma biotécnica com inúmeras vantagens para a produção de bovinos. Para a realização da IATF, as fêmeas bovinas devem receber um protocolo farmacológico que induz a ovulação de forma sincronizada. Esse protocolo inicia com a inserção de um dispositivo impregnado com progesterona que deve permanecer no fundo vaginal da fêmea por tempo determinado. O presente relato tem por objetivo descrever a remoção de um implante impregnado com progesterona que foi encontrado na cavidade abdominal de uma novilha. Durante um atendimento reprodutivo de rotina em uma propriedade rural, uma novilha da raça Jersey, recém-adquirida, com histórico de ter sido submetida à IATF, foi avaliada para diagnóstico de gestação. No exame a novilha não estava gestante e apresentava um cisto folicular ovariano. A novilha foi submetida novamente à IATF em que foi inserido e removido um implante, com isso o cisto regrediu e ao inseminar a novilha não foi possível passar a cérvix com o aplicador. Vinte dias após a inseminação a novilha manifestou estro e ao ser avaliada para nova inseminação, foi identificado um implante solto na cavidade abdominal da novilha. Foi realizada uma laparotomia pelo flanco esquerdo e o implante foi removido. Após a recuperação da cirurgia a novilha foi inseminada e novamente e ficou gestante. Os protocolos de IATF devem ser realizados por profissionais capacitados para evitar problemas como a presente situação em que um implante foi encontrado na cavidade abdominal de uma novilha.(AU)

The fixed-time artificial insemination (FTAI) is a biotechnique with numerous advantages for cattle production. In order to perform the FTAI, the cows must receive a pharmacological protocol to induce ovulation in a synchronized way. This protocol begins with the insertion of a device impregnated with progesterone that must remain in the vaginal fundus of the cow for a specific period of time. This report aims at describing the removal of a progesterone impregnated implant that was found in the abdominal cavity of a heifer. During a routine reproductive service in a rural property, a recently acquired Jersey heifer, with history of having been submitted to FTAI, was evaluated for pregnancy diagnosis. At the exam, it was observed that the heifer was not pregnant and presented an ovarian follicular cyst. The heifer was then submitted to FTAI again, where an implant was inserted and removed. This made the cyst to recede, and upon subsequent insemination, the applicator was not able to pass the cervix. Twenty days after insemination, the heifer was in estrus and when it was evaluated for insemination, a loose implant was identified in the abdominal cavity of the heifer. A laparotomy was performed through the left flank and the implant was removed. After recovery from the surgery, the heifer was inseminated again and became pregnant. The FTAI protocols should only be carried out by trained professionals to avoid problems such as the one presented herein, where an implant was found in the abdominal cavity of a heifer.(AU)

La inseminación artificial a tiempo fijo (FTAI) es una biotécnica con numerosas ventajas para la producción de ganado. Para realizar FTAI, las hembras bovinas deben recibir un protocolo farmacológico que induzca la ovulación de forma sincronizada. Este protocolo comienza con la inserción de un dispositivo impregnado con progesterona que debe permanecer en el fondo vaginal de la hembra durante un tiempo específico. Este informe tiene como objetivo describir la extracción de un implante impregnado de progesterona que se encontró en la cavidad abdominal de una novilla. Durante la atención reproductiva de rutina en una propiedad rural, se evaluó el diagnóstico de preñez de una novilla de Jersey recién adquirida con antecedentes de someterse a FTAI. En el examen, la novilla no estaba embarazada y tenía un quiste folicular ovárico. La novilla fue nuevamente sometida a FTAI, en la cual se insertó y removió un implante, con esto el quiste retrocedió y al inseminar a la novilla no fue posible pasar el cérvix con el aplicador. Veinte días después de la inseminación, la vaquilla manifestó estro y cuando se evaluó para una nueva inseminación, se identificó un implante suelto en la cavidad abdominal de la vaquilla. Se realizó una laparotomía a través del flanco izquierdo y se extrajo el implante. Después de recuperarse de la cirugía, la novilla fue inseminada y nuevamente quedó embarazada. Los protocolos FTAI deben ser realizados por profesionales capacitados para evitar problemas como la situación actual donde se encontró un implante en la cavidad abdominal de una novilla.(AU)

Protocolo para la citología vaginal directa de ratas de laboratorio / Protocol for direct vaginal cytology of laboratory rats

Introducción: La citología vaginal directa es un método muy utilizado para la evaluación del ciclo estral de las ratas de laboratorio, pero la información acerca de los procedimientos e interpretación de los resultados aparece disgregada en la literatura, lo cual dificulta su empleo en los estudios de reproducción. Objetivo: Proponer un protocolo para la realización de la citología vaginal directa de ratas de laboratorio y la interpretación de los resultados. Material y métodos: Se combinó la información de la literatura y la experiencia de 10 años de estudios de reproducción, en los que se han empleado un total de 250 ratas Wistar hembras, siguiendo preceptos éticos establecidos. Se describen los procedimientos para la obtención de las muestras, mediante lavado vaginal, así como para su observación y análisis en estado húmedo, con microscopio óptico y cámara digital acoplada. Resultados: Se describen los tipos celulares principales presentes en el lavado vaginal y las características que permiten identificar cada fase o estado de transición del ciclo estral. Se discuten aspectos a considerar en la interpretación de los resultados, que incluye la relación con los cambios hormonales, los cuidados en la obtención de la muestra y la influencia de factores ambientales. Se muestran imágenes y figuras representativas para ilustrar el texto. Conclusiones: El trabajo constituye un protocolo para el estudio del ciclo estral de ratas de laboratorio, mediante la citología vaginal directa. Provee métodos no invasivos, sencillos y económicos, así como conocimientos esenciales para la interpretación de los resultados, que integran una guía de gran utilidad para los estudios experimentales de reproducción(AU)

Introduction: Direct vaginal cytology is a widely used method for the evaluation of the estrous cycle of laboratory rats, but the information about the procedures and interpretation of results is dispersed through literature, making its use difficult in investigations on reproduction. Objective: To propose a protocol for performing direct vaginal cytology of laboratory rats as well as for the interpretation of the results. Material and methods: The information obtained from literature and the experience of 10 years of investigation on reproduction in 250 female Wistar rats were combined following the established ethical principles. The procedures for obtaining samples by vaginal washing and by observation and analysis in humid state with light microscope equipped with digital camera were described. Results: The main types of cells present in the vaginal washing and the characteristics that allow us to identify each phase or transitional phases of the estrus cycle are described. Aspects to take into consideration in the interpretation of the results, which include the association between hormonal changes, the cares in the obtaining of the sample and the influence of environmental factors, are discussed. Representative images and figures are included to illustrate the text. Conclusions: The work consists of a study protocol of the estrus cycle of laboratory rats by direct vaginal cytology. It provides noninvasive, simple and cost-reducing procedures as well as essential knowledge for the interpretation of results which integrate a very useful guideline for experimental investigations on reproduction(AU)

Condición corporal y reinicio de la actividad ovárica posparto en vacas Holstein en Ecuador / Corporal condition and restart of the ovarian postpartum on Holstein cows in Ecuador

RESUMEN Objetivo. Determinar la influencia de la condición corporal al parto (CCP) en el reinicio de la actividad ovárica (RAO) posparto de la vaca Holstein en la región andina de Ecuador. Materiales y métodos. Se trabajaron 30 vacas. Se determinaron el momento de aparición del folículo dominante (FD), de ovulación y de actividad luteal; la duración del ciclo estral, el volumen del cuerpo lúteo (CL) y las concentraciones de progesterona (P4) en suero sanguíneo. Los estadígrafos descriptivos de las variables del RAO y sus indicadores se compararon según la CCP mediante una prueba de t-Student para muestras independientes. Se evaluó la asociación entre la CCP y el RAO posparto mediante un estudio caso control. Resultados. La duración del ciclo estral fue 23.10 días, el 46.67% de las vacas tuvo ciclos normales y el 53.33% ciclos anormales. El FD, la ovulación y la actividad luteal ocurrieron a los 16.63, 27.76 y 41.38 días posparto, respectivamente; antes (p<0.05) en vacas con CCP ≥ 3.5; en las que fueron mayores (p<0.05) el volumen del CL y las concentraciones de P4. La CCP se correlacionó (p<0.05) con los parámetros del RAO. Las vacas con CCP <3.5 puntos, tienen 10.50 veces más probabilidades de tener RAO tardío que las que tienen CCP ≥ de 3.5 puntos. Conclusiones. El RAO fue temprano, sobre el influyó la CCP, la que constituyó un factor de riesgo (p<0.05) para que las vacas tengan un RAO tardío.

ABSTRACT Objective. To determine the influence of corporal composition at delivery (CCD) on the ovarian postpartum restart (OPR) of the Holstein cow in the Andes Region in Ecuador. Materials and methods. 30 cows were produced. All of the following moments were determined: the appearing of the dominant follicle (DF), the ovulation and luteal activity; the duration of the estrous cycle, the volume of the luteum body (LC) and the progesterone concentrations (P4) on blood serum. Descriptive statisticians of the OPR variables and its indicators were compared according to the BC, by means of a t-Student test for independent samples. The relationship between the BC and the postpartum OPR through a case-control case was assessed. Results. The duration of the oestrous cycle was 23.10 days, 46.67% of the cows had regular cycles and 53.33% were abnormal cycles. The DF, the ovulation and the luteal activity were seen at 16.63, 27.76 and 41.38 after postpartum, respectively; before (p<0.05) on cows with BC ≥ 3.5; in which both the (p<0.05) and the volume of the LC and P4 concentrations were higher. The BC was correlated with (p<0.05) with the OPR parameters. The cows with <3.5 BC points, are 10.50 times more prompt to have a late OPR than those with a ≥ de 3.5 points BC. Conclusions. The OPR was early, BC had an influence on it, which constituted a major (p<0.05) risk factor on cows having a late OPR.

Ultrasound evaluation of female reproductive system in free ranging Giant Anteater (Myrmecophaga tridactyla): case report / Avaliação ultrassonográfica do sistema reprodutor feminino em tamanduá-bandeira de vida livre (Myrmecophaga tridactyla): relato de caso

An adult, female, 31kg body weight, free range Myrmecophaga tridactyla was referred for medical consultation due to apathy, dehydration, intense flatulence and fetid stools. The animal was submitted to chemical restraint and physical examination, blood count, fecal analysis, and vaginal cytology and abdominal ultrasonography were performed. Good nutritional status and clinical variables within the normal range were observed at physical examination. At vaginal cytology leukocytes, spermatozoa and a large proportion of cornified cells (superficial) were observed, indicating estrus and recent copula. At ultrasound examination it was possible to locate, identify, evaluate and measure the ovaries and the uterine structures, cervix, body, lumen, myometrium and endometrium, a fact never reported in the literature for this species. These data can be used as reference for clinical evaluation of the reproductive tract in Myrmecophaga tridactyla females considered vulnerable species, for the diagnosis of reproductive pathologies, biotechnologies application or estrous cycle evaluation.(AU)

Uma fêmea, com 31kg de peso corporal, de Myrmecophaga tridactyla, de vida livre, foi apresentada para consulta médica em razão de apatia, desidratação, flatulência intensa e fezes fétidas. O animal foi submetido à contenção química e foram realizados exame físico, hemograma, análise fecal, citologia vaginal e ultrassonografia abdominal. Ao exame físico, foi determinado bom estado nutricional e variáveis clínicas dentro da faixa de normalidade. Na citologia vaginal, foram observados leucócitos, espermatozoides e uma grande proporção de células cornificadas (superficiais), indicando estro e cópula recente. No exame ultrassonográfico, foi possível localizar, identificar, avaliar e mensurar os ovários e as estruturas uterinas, o colo do útero, o corpo do útero, o lúmen, o miométrio e o endométrio, fato nunca relatado na literatura para essa espécie. Esses dados podem ser utilizados como referência para avaliação clínica do trato reprodutivo de fêmeas de Myrmecophaga tridactyla considerada espécie vulnerável, para o diagnóstico de patologias reprodutivas, aplicação de biotecnologias ou avaliação do ciclo estral.(AU)

Evaluation of embryo collection and transfer days on pregnancy rate of Mangalarga Marchador mares during the breeding season / Evaluación de los días de recolección y transferencia de embriones sobre las tasas de preñez en yeguas Mangalarga Marchador durante la estación de monta / Avaliação do dia da colheita e da transferência de embriões equino da raça Mangalarga Marchador durante a estação de monta

Abstract Background: Proper timing for embryo collection and transfer in horses -which is critical for the success of this biotechnology- is still debated. Additionally, there is little information on this technology under tropical conditions. Objective: To determine the best day for collection and transfer of embryos in Mangalarga Marchador mares under Brazilian northeast's conditions. Methods: Donors (n= 30) and recipients (n= 76) in diestrus phase were selected based on both clinical and gynecology examinations. Estrus was induced on both donor and recipient mares by intramuscular injection of 5 mg Dinoprost, aiming to obtain an ovulation interval of -1 to +3 between recipient and donor. Ovulation was induced with buserelin acetate when the largest follicle reached at least 35 mm in diameter. At this time, mares were subjected to artificial insemination at 48-hour intervals until ovulation. The embryos were collected on days 7, 8, and 9 after ovulation. Results: The embryo collection on day 8 was more efficient (p<0.05) than on day 7, but it was not more effective (p>0.05) than day 9, which presented the same efficiency (p>0.05) as day 7. From a total of 76 embryos transferred to the recipients, that were between days 4 and 9 after ovulation, there was no influence (p>0.05) of the day of transfer on pregnancy rate. Conclusions: The embryo collection must be performed on day 8 after ovulation, and transfer can be performed on any day of that interval (4-9) without affecting the pregnancy rate.

Resumen Antecedentes: El momento mas apropiado para la recolección y transferencia de embriones en equinos -que es fundamental para el éxito de esta biotecnología- continua siendo sujeto de estudio. Además, es escasa la información sobre esta tecnología en condiciones tropicales. Objetivo: Determinar el momento mas adecuado para la recolecta y transferencia de embriones en yeguas Mangalarga Marchador, en las condiciones del nordeste Brasileño. Métodos: Donadoras (n= 30) y receptoras (n= 76) en la fase de diestro se seleccionaron con base en los exámenes clínicos y ginecológicos. El estro de las yeguas donadoras y receptoras fue inducido con 5 mg de Dinoprost, vía intramuscular, intentando obtener un intervalo de ovulación de -1 a +3 entre la receptora y la donadora. La ovulación fue inducida con acetato de buserelina cuando el folículo mayor alcanzó 35 mm de diámetro. En ese momento, las yeguas fueron sometidas a inseminación artificial en intervalos de 48 horas hasta la ovulación. Los embriones fueron recolectados en los días 7, 8 y 9 después de la ovulación. Resultados: La recolecta de embriones en el día 8 fue más eficiente (p<0,05) que en el día 7, pero no fue más efectivo (p>0,05) que en el día 9, el cuál presentó la misma eficiencia (p>0,05) que en el día 7. De un total de 76 embriones transferidos a las receptoras, que se encontraban entre el día 4 y 9 después de la ovulación, no se registró influencia (p>0,05) del día de la transferencia en la tasa de preñez. Conclusiones: La recolecta embrionaria debe ser realizada el día 8 después de la ovulación, y la transferencia puede ser realizada en cualquier día de este intervalo (4 a 9) sin que se afecte la tasa de preñez.

Resumo Antecedentes: A importância do momentoda colheita e da transferência do embrião equino para o sucesso dessa biotécnica em equino continua sem ser completamente entendida. Adicionalmente, existe pouca informação sobre essa tecnologia em condições tropicais. Objetivo: Determinar o melhor dia para colheita e para transferência de embriões em eguas manga larga marchador nas condições do nordeste brasileiro. Métodos: Doadoras (n = 30) e receptoras (n = 76) na fase de diestro foram selecionadas com base nos exames clínico e ginecológicos. O estro das éguas doadoras e receptoras foi induzido com 5 mg de Dinoprost administrado por via intramuscular, buscando obter um intervalo de ovulação de -1 a +3 entre a receptora e a doadora. A ovulação foi induzida com acetato de buserelina quando o foliculo maior alcançou o tamanho de 35 mm de diâmetro. Nesse momento, as éguas foram submetidas a inseminação artificial em intervalos de 48 horas até a ovulação. Os embriões foram colhidos nos dias 7, 8 e 9 depois da ovulação. Resultados: A colheita de embriões no dia 8 foi mais eficiente (p<0,05) do que no dia 7, porem não foi mais efetivo (p>0,05) do que o dia 9, o qual apresentou a mesma eficiência (p>0,05) que o dia 7. De um total de 76 embriões transferidos para as receptoras que se encontravam entre os dias 4 e 9 depois da ovulação, não se registrou influência (p>0,05) do dia da transferência sobre a taxa de prenhez. Conclusões: A colheita embrionária deve ser realizada no dia 8 depois da ovulação, e a transferência pode ser realizada em qualquer dia desse intervalo (4-9) sem que a taxa de prenhez seja afetada.

Melatonin may prevent or reverse polycystic ovary syndrome in rats

SUMMARY OBJECTIVE To evaluate the ovarian effects of melatonin (Mel) in a rat model of polycystic-ovary-syndrome (PCOS) before and after permanent estrus induction. METHODS Thirty-two adult-female rats with regular estrous cycle were equally divided into four groups: 1) GCtrl - at estrous phase. 2) GPCOS - at permanent-estrous phase. 3) GMel1 - treated for 60 days with Mel (0.4 mg/Kg) during permanent estrus induction and 4) GMel2 - rats with PCOS and treated for 60 days with Mel. After that, the animals were euthanized, and the ovaries were removed and processed for paraffin embedding. Sections were stained with H.E. for histomorphometry or subjected to immunohistochemistry for Ki-67 and cleaved caspase-3 (Casp-3) detections. RESULTS The GPCOS showed lack of corpus luteum and several ovarian cysts, as well as interstitial-like cells. The presence of corpus luteum and a significant increase in primary and antral follicles were observed in Mel-treated groups, which also showed a decrease in the number of ovarian cysts and in the area occupied by interstitial-like cells. These results were more evident in GMel1. The percentage of Ki-67-positive cells was significantly higher in the Mel-treated groups, mainly in the GMel2, as compared to GPCOS. On the other hand, the percentage of Casp-3-positive cells was significantly lower in granulosa cells of GMel1, whereas it was significantly higher in the interstitial-like cells of GMel2, in comparison to GPCOS. CONCLUSION Melatonin administration prevents the permanent estrus state in the PCOS rat model. This effect is more efficient when melatonin is administered before permanent estrus induction.

RESUMO OBJETIVO Avaliar os efeitos ovarianos da melatonina (Mel) em ratas com síndrome dos ovários policísticos (SOP) antes e após a indução do estro-permanente. MÉTODOS Trinta e duas ratas com ciclos estrais regulares foram igualmente divididas em quatro grupos: 1) GCtrl - fase de estro. 2) GSOP - fase de estro-permanente. 3) GMel1 - tratadas por 60 dias com Mel (0,4 mg/kg) durante a indução do estro-permanente e 4) GMel2 - ratas com SOP e tratadas com Mel. Após eutanásia dos animais, os ovários foram processados para inclusão em parafina. Cortes foram corados com H.E ou submetidos à imuno-histoquímica para detecção de Ki-67 e caspase-3 clivada (Casp-3). RESULTADOS O GSOP mostrou ausência de corpos lúteos e vários cistos ovarianos, além de inúmeras células intersticiais. A presença de corpos lúteos e o aumento significativo dos folículos primários e antrais foram observados nos grupos tratados com Mel, os quais também mostraram diminuição no número de cistos ovarianos e na área ocupada pelas células intersticiais. Esses resultados foram mais evidentes no GMel1 do que no GMel2. A porcentagem de células Ki-67 positivas foi significativamente maior no GMel1 e no GMel2, sendo mais evidente no GMel2, em comparação ao GSOP. Por outro lado, a porcentagem de células positivas à Casp-3 foi menor nas células da granulosa do GMel1 e maior nas células intersticiais do GMel2, em comparação ao GSOP. CONCLUSÃO A administração de melatonina previne o estado de estro-permanente em ratas com SOP. Esse efeito é mais eficiente quando a melatonina é administrada após indução do estado de estro-permanente.

Tetrapleura tetraptera Extract Inhibited Luteinizing Hormone and Estrogen Secretion in Clomiphene Citrate Treated Female Wistar Albino Rats

Tetrapleura tetraptera stem bark has been reported to cause inhibition of luteinizing hormone release in cultured rat pituitary cells. Hence, we investigated the effects of Tetraptera tetrapleura pod extract on follicle stimulating hormone, luteinizing hormone, cortisol, progesterone and estrogen. Thirty non-pregnant female wistar albino rats were divided into group A - D. Group A rats were used as Control. Group B rats were administered 1 mg/kg/day of clomiphene citrate orally. Group C rats were administered 200 mg/kg of extract only, whereas group D rats were administered 1 mg/kg /day of Clomiphene citrate plus 200 mg/kg of extract. At the end of 14 days experiment, group A, B and D were found in proestrus phase and group C in diestrus phase. FSH and cortisol levels remained unchanged. Group C and D rats produced significant reduction (P < 0.05) in LH and estrogen levels in prolonged proestrus and normal diestrus respectively. Progesterone level was significantly high (P < 0.05) in the group C rats. The reduced LH level could be due to the anti-estrogenic effect of extract during proestrus when LH secretion is expected to surge. But co-administration resulted in high progesterone secretion, suggesting extract may have influenced progesterone secretion in group D rats simultaneously administered with clomiphene citrate and extract. The above findings indicated that Tetrapleura tetraptera pod extracts inhibited luteinizing hormone and estrogen even when co-administered with clomiphene citrate.

Immuno Localization of Estrogen Receptor (ERα) and Progesterone Receptor (PR) in Uterus of Buffalo during Follicular and Luteal Phases of Estrous Cycle

The tissue distribution of estrogen receptor alpha (ERα) and progesterone receptor (PR) was examined using immunohistochemical technique. Image analysis was done to quantify the immune reactivity. The ERα and PR was localized in luminal epithelium, glandular epithelium, stromal cells, endothelial cells and myometrium and few cells in perimetrium. The immuno staining was observed in the nuclei of cells, however, faint cytoplasmic staining for PR was also observed. Variations were seen in the different tissue compartments of the uterus and during the different phases of the estrous cycle. Significantly higher number of ERα positive cells was observed in lamina epithelialis as compared to stromal cells and smooth muscle cells in myometrium. Significantly higher percentage of ERα positive cells was observed in the lamina epithelialis and lining epithelium of endometrial glands during follicular phase as compared to the luteal phases of estrous cycle (P < 0.05). Higher number of PR positive cells was observed in lamina epithelialis as compared to stromal cells and smooth muscle cells in myometrium (P < 0.05). Higher percentage of PR positive cells was observed in the lamina epithelialis during follicular phase as compared to the luteal phases of estrous cycle (P < 0.05). There was no significant difference in the immuno reactivity in stromal cells, lining epithelium of endometrial glands and smooth muscle cells of myometrium during the phases of estrous cycle. The study concluded that ERα and PR expressions were higher during follicular phase as compared to the luteal phase

Valiação do efeito do extrato de Tribulus Terrestris l. Na ocorrência do ciclo estral de camundongos suíços fêmeas ovariectomizadas e não ovariectomizadas / Evaluation of the extract effect of Tribulus terrestris L. on the occurrence of the estral cycle of ovariectomized and not ovariectomized female swiss mice

Introdução: a infertilidade ou incapacidade de gerar filhos é um problema que acomete parte da população. Seu tratamento geralmente é feito pela reposição hormonal, no entanto, terapias alternativas com o uso de plantas medicinais vêm sendo adotadas. Objetivo: diante do exposto, o presente estudo teve por objetivo avaliar o efeito do extrato do Tribulus terrestris L. na ocorrência do ciclo estral em camundongos fêmea ovariectomizadas e não ovariectomizadas. Métodos: foram utilizados 28 camundongos suíços fêmeas e adultas, divididas em quatro grupos de 7 animais: grupo sem ovariectomia e sem suplementação ou controle, grupo com ovariectomia e sem suplementação, simulando a infertilidade, grupo tratado com Tribulus terrestris (10mg/kg) com ovariectomia e grupo tratado com Tribulus terrestris L. (10mg/kg) sem ovariectomia. Os extratos foram administrados por gavagem durante 21 dias. O ciclo estral foi analisado ao longo deste mesmo período. Resultados: notou-se aumento significativo na fase proestro do ciclo estral no grupo ovariectomizado e suplementado quando comparado ao grupo ovariectomizado e sem suplementação. Conclusão: o aumento significativo na ocorrência do proestro corresponde a um período do ciclo estral relacionado à ocorrência da ovulação.

Introduction: infertility or inability to generate children is a problem that affects part of the population. Its treatment is usually done by hormone replacement, however, alternative therapies with the use of medicinal plants have been adopted. Objective: in view of the above, the present study aimed to evaluate the effect of Tribulus terrestris L. extract on the occurrence of the estrous cycle in ovariectomized and non ovariectomized mice. Methods: twentyeight female and adult Swiss mice were divided into four groups of 7 animals: group without ovariectomy and without supplementation or control, group with ovariectomy and no supplementation simulating infertility, group treated with Tribulus terrestris L. (10mg / kg) with ovariectomy and group treated with Tribulus terrestris L. (10mg / kg) without ovariectomy. The extracts were administered by way of gavage for 21 days. The estrous cycle was analyzed over this same time. Results: there was a significant increase in the proestrus phase of the estrous cycle in the ovariectomized group and supplemented when compared to the ovariectomized group and without supplementation. Conclusion: the significant increase in the occurrence of proestrus corresponds to a period of the estrous cycle related to the occurrence of ovulation.

Effects of RN-1734 injection into hypothalamus PO/AH region on increase of rat body temperature induced by progesterone / 中国药理学通报

Aim: To verify the involvement of transient receptor potential vanilloid 4 (TRPV4) in the process of progesterone induced body temperature rise in female rats during their sexual cycle. Methods: The body temperature and progesterone concentration at different stages of the normal female rats' sexual cycle were measured. The ovariectomized rats were given different doses of progesterone and their body temperature were measured. Female rats were administered with RN-1734, a specific antagonist of TRPV4 in the preoptic-anterior hypothalamus area (PO/AH) at the metestrus to observe the change of rats body temperature. Furthermore, RN 1734 was injected into the PO/AH area of ovariectomized rats which were preinjected with progesterone. The effect of progesterone on the body temperature of rats and the fluctuation of body temperature after blocking TRPV4 were observed. Results: There was a positive correlation between body temperature and progesterone doses in female rats at different stages of estrus cycle. In ovariectomized rats, different doses of progesterone were administered, indicating a dose-dependent increase in body temperature. RN- 1734 was injected to PO/AH 2 hours before the maximum body temperature on normal metestrus rats. It was observed that the increase range of body temperature decreased significantly after RN-1734 injection. This study also showed that RN-1734 significantly reduced the increase range of body temperature in ovariectomized rats administered with progesterone. Conclusions: The specific antagonist TRPV4 injected into the thermoregulation center could reduce the increase of body temperature in metestrus of normal rats, suggesting that TRPV4 may be involved in the process of the increase of rat body temperature induced by progesterone.

Effects of radices paeoniae alba extract on erp and sert in hippocampus of rat model of pms liver-qi inverse syndrome / 中国药理学通报

Aim To investigate the effect of Radices Paeoniae Alba extract on estrogen receptor (3 ( ERp ) and serotonin transporter(SERT) in the hippocampus of rat model of premenstrual syndrome( PMS) liver-qi inverse syndrome. Methods The rats were randomly divided into the normal group, the model group, the Radices Paeoniae Alba extract group, the fluoxetine group and the ER(3 agonist group by the vaginal smear microscopy and the open field score. The model group rats were prepared by electrical stimulation to prepare PMS liver-qi inverse syndrome. After five days of administration, the hippocampal tissues of each group were separated. ERp and SERT mRNA and protein expression in each group were determined by RT-PCR and immunofluorescence histochemical method. Results During the estrous reception period, there was no significant difference in the behavior score of the open- field test and the expression of ERp and SERT mRNA and protein in the hippocampus of each group. Estrous non-reception period; compared with normal rats, the total distance of open field test in model rats increased significantly. The expression of ER(3 mRNA in hippocampus significantly decreased and SERT mRNA significantly increased. In model group, the pyramidal cells in hippocampal CA1 and CA3 brain areas of rats were irregularly arranged, and the number of ERp positive cells and protein expression decreased. The number of SERT positive cells and protein expression were significantly up-regulated. After the Radices Paeoniae Alba extract was given, the above indexes were significantly improved, and no significant difference was found between them and fluoxetine group and ER agitator group. Conclusions Radices Paeoniae Alba extract may adjust the PMS card of diseases with inverse nega-tive emotions possibly by improving the hippocampus ER|3 and SERT mRNA and protein expression.

Regulation of estrous cycle by Cynodon dactylon in letrozole induced polycystic ovarian syndrome in Wistars albino rats / 대한해부학회지

Follicular and luteal morphometry, progesterone concentration and early gestation in Holstein cows (Bos Taurus) at high altitude in the tropics (Colombia) / Morfometría folicular y luteal, concentración de progesterona y éxito de la gestación en vacas Holstein (Bos Taurus) en el trópico alto (Colombia)

Abstract Objectives. The aim of this study is to evaluate the relationship among ovulatory follicle (OF) size, corpus luteum (CL) volume, and progesterone (P4) serum levels with pregnancy success. Materials and methods. Nineteen Holstein cows located in Bogotá, Colombia with a history of 2 to 6 previous calving were used in the study. Following 40 day postpartum, two consecutive phases were evaluated as follows: 1) estrous cycle; 2) early pregnancy or return to estrus after Artificial Insemination (AI). Ultrasound exam was performed twice daily after first sign of estrus to evaluate OF diameter and CL volume, and serum P4 levels were evaluated on days 6, 9, 12 and 15 after ovulation. Cows were inseminated 12 hours post estrus signs and pregnancy was diagnosed 30 days post AI. Results. 47.36% of the cows were diagnosed as pregnant after AI. Pregnant cows had smaller OF diameters (17.85±2.39 mm) than non-pregnant females (21.10±2.86 mm) (p<0.05). Cows with smaller OF were more likely to become pregnant (OR=0.624, IC=95% (0.4-0.9) (p<0.05). There were non significant differences in the CL volume (p=0.10) and P4 serum values (p=0.39) between pregnant and no pregnant cows on days 6, 9, 12 and 15 post ovulation. Serum P4 levels were not correlated to CL size and reproductive status. Conclusions. This study shows that there was not significant difference in serum P4 levels and the CL volume when comparing pregnant with non-pregnant cows. A relationship was found between the OF diameter and the CL volume. Small OF diameter was a factor associated with early pregnancy.

Resumen Objetivo. Evaluar la relación entre el diámetro del folículo ovulatorio (FO), el volumen del cuerpo lúteo (CL), los niveles séricos de progesterona (P4) con el éxito de la gestación. Materiales y métodos. En 19 vacas Holstein que habían tenido 2 a 6 partos ubicadas en Bogotá, se evaluaron dos fases consecutivas a partir del día 40 postparto, la primera correspondió al ciclo estral y la segunda correspondió a la gestación temprana o repetición de celo. En cada fase se detectó el celo, se realizó ultrasonografía para evaluar el diámetro del FO, confirmar ovulación, y el volumen del CL los días 6, 9, 12 y 15; en estos días también se evaluó los niveles séricos de P4. En la segunda fase se realizó inseminación artificial (IA) y se diagnosticó la gestación 30 días post-IA. Resultados. El 47.36% de las vacas se diagnosticaron como gestantes y el 52.63% como no gestantes. Las gestantes presentaron diámetros de FO menores 17.85±2.39 mm al de las no gestantes (21.10±2.86 mm; p<0.05). Las vacas que presentaron diámetros de FO más pequeños tuvieron mayor posibilidad de quedar gestantes (OR=0.624, IC=95% (0.4-0.9) (p<0.05). Los animales gestantes y no gestantes presentaron similares volúmenes de CL (p=0.10) y niveles séricos de P4 (p=0.39) los días 6, 9, 12 y 15. Conclusiones. No hubo diferencias en los niveles séricos de p4 y el volúmen del CL. Vacas con FO de menor diámetro tuvieron mayor probabilidad de gestación. Otras variables como CL y niveles de P4 no fueron predictivos del éxito de la gestación.

Pretentious genomic selection signatures in CYP19A1 gene associated with silent estrous behavior in water buffalo in Pakistan

Background: Poor reproductive efficiency of river buffalos hampers the production capabilities of animals. Buffalos are mainly considered poor breeders owing to the constrained expression of estrus behavior. Failure to display heat signs is an indication of improper functionality of signaling peptides to trigger on a series of behavioral changes, which can be detectable by breeders for timely insemination of females. This might cause an animal to be a repeat breeder. Genomic variations underlying synthesis of signaling peptides can be a useful marker to select superior animals with better reproductive efficiency. In this context, the current study was designed to analyze the CYP19A1 gene in Nili-Ravi buffalo. Results: A total of 97 animals were selected and were divided into two groups on the basis of their heat score. PCR amplification and sequencing of the amplicons were performed using the specific sets of primer, and then, sequences were analyzed for novel variants. A total of 11 polymorphic sites were identified illustrating phenotypic variation in the heat score. Most of the loci were found homologous. Single Nucleotide Polymorphisms (SNPs) were analyzed for association with silent estrus. A three-dimensional protein model was also generated to locate the position of exonic SNPs. Conclusion: This study illustrated that polymorphic sites in the CYP19A1 gene provided potential markers for selection of buffalos with better estrus behavior.

Parámetros sanguíneos y perfil de hormonas reproductivas de hembras de Choloepus hoffmanni en cautiverio / Blood parameters and reproductive hormone profile of female Choloepus hoffmanni in captivity

Resumen El uso de técnicas no invasivas ni estresantes para determinar perfiles hormonales, como la medición de esteroides fecales, ha incrementado la comprensión de la fisiología reproductiva en animales silvestres. Debido a la escasa información con respecto a perfiles hormonales reproductivos del perezoso de dos dedos, Choloepus hoffmani, se realizó un estudio en hembras en cautiverio en el centro de rescate "Sloth Sanctuary" (Cahuita, Limón, Costa Rica) con el fin de determinar (i) la confiabilidad de la extracción de progesterona y estradiol en heces, y su cuantificación en el analizador AIA-360®, (ii) evaluar los parámetros sanguíneos en esta especie y (iii) establecer si existe una correlación entre los esteroides plasmáticos y fecales. El estudio se realizó en un periodo de tres meses, durante noviembre de 2013 a enero de 2014, con un total de 208 muestras de heces provenientes de cinco hembras sexualmente maduras, con peso promedio de 6.32 kg. El promedio de las concentraciones medianas en las heces de las cinco hembras fue 124.21 ng/g para progesterona y 1 708.95 pg/g de estradiol. En plasma, los valores de mediana fueron 1.26 ng/mL con un mínimo de 0.32 ng/mL y 12.84 ng/mL como valor máximo; los valores plasmáticos de estrógeno se encontraron por debajo del límite de detección del equipo (25 pg/mL). Aunque no se encontró una correlación estadísticamente significativa entre la progesterona plasmática y la fecal, nuestros datos sugieren que los eventos plasmáticos se reflejan en heces durante los dos días posteriores. Asimismo, los niveles de progesterona se mantuvieron elevados durante la primera mitad de noviembre, y posteriormente mostraron una reducción importante en todas las hembras. Nuestros resultados demuestran que las extracciones en heces y su medición en el AIA-360® permiten la detección y el seguimiento de variaciones hormonales en C. hoffmani, aunque no remplaza las mediciones plasmáticas para determinar valores absolutos.

Abstract In wild animal species, the use of non-invasive and non-stressful procedures to determine hormone profiles, such as fecal steroid measurements, has considerably increased the comprehension of their reproductive physiology. Since there is limited information related to the reproductive hormone profiles of the two-toed sloth, Choloepus hoffmani, a study was conducted in captive specimens at the "Sloth Sanctuary" (Cahuita, Limón, Costa Rica), in order to determine: (i) the reliability of the fecal progesterone and estrogen extraction and its quantification with an AIA-360® analyzer, (ii) assess blood parameters in this species and (iii) evaluate if there is a correlation between fecal and plasmatic steroids. The study was performed over a three-month period, from November, 2013 to January, 2014, with a total amount of 208 fecal samples collected from five sexually mature females weighing 6.32 kg in average. The average of the median concentrations of progesterone in feces of the five females was 124.21 ng/g, and 1 708.95 pg/g for estrogen. The average minimal and maximal values were 50.96 ng/g and 1 057.46 ng/g for progesterone and, 1 191.77 pg/g and 2 159.24 pg/g for estradiol. In plasma, progesterone median values were 1.26 ng/mL, showing a minimum of 0.32 ng/mL and 12.84 ng/mL as maximum values. The plasmatic estrogen levels were below the detection limit of the equipment (25 pg/mL). Although there was no strong statistical correlation between the fecal and plasmatic progesterone fluctuations, our data suggests that the plasmatic events are mostly reflected in feces two days afterwards. Also, the levels of progesterone were elevated during the first half of November and, subsequently, showed a successive and important reduction in all the females tested. Finally, our results demonstrated that fecal steroid extractions and their measurement in a AIA-360®, allowed the successful detection and represents an alternative non-invasive determination of hormone profiles in C. hoffmani. Rev. Biol. Trop. 66(1): 280-292. Epub 2018 March 01.

Effects and mechanism of cyclophosphamide on the ovarian structure and function of rats with premature ovarian failure / 解放军医学杂志

Objective To establish the premature ovarian insufficiency (POI) rat model with cyclophosphamide (CTX),and investigate the effects and mechanism of CTX on the ovarian structure and function.Methods Fifty female Sprague-Dawley (SD) rats were randomly divided into model group and control group.Rats in model group received intraperitoneal injection of loading dose CTX (50mg/kg),and maintenance dose of 8mg/(kg.d) for 14 days.Rats in the control group were given the same amount of saline during the same period.The modeling effects were judged by observation and comparison of estrous cycle,levels of sex hormone and morphological changes of organs between the two groups;the apoptosis of follicular granulose cell were detected by TUNEL,the contents of inflammatory cytokines in tissue homogenates were detected by ELISA,and the expressions of apoptosis related proteins were measured by Western blotting.Results Compared with control group,the estrous cycle in model group was disordered;the levels of serum anti-mullerian hormone (AMH) and estrogen (E2) decreased significantly (P＜0.01) and those of follicle stimulating hormone (FSH) increased markedly (P＜0.01);the quantity of follicles decreased obviously (P＜0.05);the endometrium atrophied,the uterine wall thinned and the glands decreased in number.Compared with the control group,the apoptosis of follicular granulose cells increased in model group;the contents of TNF-α,IL-1β and IL-6 in the tissue homogenate increased significantly (P＜0.01),the contents of vascular endothelial growth factor-α (VEGF-α) decreased markedly (P＜0.01);the expression of apoptosis related protein Bax was up-regulated remarkably (P＜0.01),while of Bcl-2 was down-regulated obviously (P＜0.01).Conclusion CTX may induce the changes of ovary structure and endocrine function,and the mechanism may be related to the local microenvironment changes and the imbalance of Bax/Bcl-2 expression in regulating the apoptosis of granulose cells.

Cardiac parameters during the estrous cycle of canine bitches / Parâmetros cardíacos durante o ciclo estral de cadelas

The cardiovascular parameters of canine bitches were assessed during the estrous cycle. A total of eleven mongrel female dogs were enrolled in a longitudinal prospective investigation. Six animals were bred during the study and were assigned into group I, in which evaluations were performed during proestrus, estrus, gestational diestrus and anestrus. The five remaining bitches were not bred and underwent evaluations during proestrus, estrus, nongestational diestrus and anestrus. The holter data showed a gradual increase in the minimum and mean heart rate along pregnancy, as well as a reduction during anestrus, which differed significantly among the distinct periods. The values for maximal heart rate documented during pregnancy were significantly lower than those recorded during anestrus, and a variation in the heart rate circadian rhythm was also found, as demonstrated by decreases at night and rises during the day. Cardiac rhythm had a similar performance in both pregnancy and anestrus. Likewise, the blood pressure, electrocardiography, and echocardiography data did not vary during the estrous cycle. The results support the role played by the autonomic nervous system during these two distinct periods in order to attain a heart rate that provides the blood needed by the female's body during the various stages of the reproductive cycle. Further studies are needed to better clarify the cardiovascular compensatory neuroendocrine events that accompany gestation in this species.(AU)

Os parâmetros cardiovasculares de fêmeas caninas foram avaliados durante o ciclo estral. Um total de onze cadelas sem raça definida foram incluídas nesta pesquisa prospectiva longitudinal. Seis animais foram colocados em reprodução durante o estudo e avaliados durante o proestro, estro, diestro gestacional e anestro. As cinco cadelas restantes não se reproduziram e foram avaliadas durante o proestro, estro, diestro não gestacional e anestro. Os dados derivados do holter indicaram aumento gradativo nas frequências cardíacas mínima e média durante a gestação, bem como redução durante o anestro, diferindo significativamente entre os distintos períodos. Os valores da frequência cardíaca máxima documentados durante a gestação foram significativamente inferiores àqueles registrados durante o anestro. Também foi identificada variação no ritmo circadiano da frequência cardíaca, conforme demonstrado por sua redução à noite e elevação durante o dia. No entanto, o ritmo cardíaco se comportou de modo semelhante tanto na gestação quanto no anestro. Da mesma forma, os dados de pressão sanguínea, eletrocardiografia e ecocardiografia não variaram durante o ciclo estral. Os resultados atestam o papel desempenhado pelo sistema nervoso autônomo ao longo desses dois períodos distintos, visando manter uma frequência cardíaca que garanta o suprimento sanguíneo necessário pelo organismo da fêmea durante os vários estágios do ciclo reprodutivo. Estudos adicionais são necessários para esclarecer mais detalhadamente os eventos neuroendócrinos e cardiovasculares compensatórios que acompanham a gestão nessa espécie.(AU)