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Objective: To evaluate the effects of Eurycoma longifolia (E. longifolia) standardized extract on the oestrous cycle, levels of reproductive hormones and histology of the ovaries of Sprague-Dawley rats. Methods: Female rats were orally treated with E. longifolia standardized extract at the dose levels of 2.5, 5.0, 10.0, 25.0, 50.0 and 100.0 mg/kg of body weight over 5 days. Vaginal smears were monitored daily within the duration and after withdrawal of the treatment before being sacrificed. The body weights of the females were recorded before and after the 5 days treatment. At the end of the experiments, blood samples were collected for determination of testosterone, oestradiol and progesterone levels. Ovaries were removed, weighed and examined for histomorphological changes. Results: The administration of E. longifolia standardized extract did not significantly alter the oestrous cycle of the rats during the 5 days treatment and after withdrawal of the treatments. This was supported by normal testosterone, oestradiol and progesterone levels as well as normal morphology of the ovaries. Conclusions: The data obtained showed that E. longifolia standardized extract did not exhibit any toxic effect on reproductive activities of female rats suggesting potential use in the management of infertility.
ABSTRACT
Objective To evaluate the effects of Eurycoma longifolia (E. longifolia) standardized extract on the oestrous cycle, levels of reproductive hormones and histology of the ovaries of Sprague-Dawley rats. Methods Female rats were orally treated with E. longifolia standardized extract at the dose levels of 2.5, 5.0, 10.0, 25.0, 50.0 and 100.0 mg/kg of body weight over 5 days. Vaginal smears were monitored daily within the duration and after withdrawal of the treatment before being sacrificed. The body weights of the females were recorded before and after the 5 days treatment. At the end of the experiments, blood samples were collected for determination of testosterone, oestradiol and progesterone levels. Ovaries were removed, weighed and examined for histomorphological changes. Results The administration of E. longifolia standardized extract did not significantly alter the oestrous cycle of the rats during the 5 days treatment and after withdrawal of the treatments. This was supported by normal testosterone, oestradiol and progesterone levels as well as normal morphology of the ovaries. Conclusions The data obtained showed that E. longifolia standardized extract did not exhibit any toxic effect on reproductive activities of female rats suggesting potential use in the management of infertility.
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Se realizó un estudio para evaluar la conducta sexual (CS) e intensidad del celo (ICel) en vacas de ganadería mestiza doble propósito (GDP) y su relación con la fertilidad (FERT) a la inseminación artificial (IA). Para ello, en vacas de dos fincas ubicadas en zona de bosque húmedo tropical de Venezuela, se registraron cinco signos conductuales secundarios de CS (SCSCS) y, a la IA, los tres signos físicos (SF): enrojecimiento de la mucosa de la vulva; presencia de moco cervical (limo) y excoriaciones y/o depilaciones en la parte trasera asociados al signo principal, aceptación quieta de la monta (AQM). Las vacas estuvieron bajo observación visual cuatro veces en horario diurno, durante una hora, separadas por intervalos de tres horas. Los animales fueron alimentados a pastoreo, suplementados con concentrado, sales y agua ad libitum. La IA se hizo siguiendo la regla AM-PM, la FERT por diagnóstico de gestación vía transrectal a los 45-60 d post-IA. A cada signo observado se le asignó un puntaje y a su ausencia 0. La AQM se valoró en 100 puntos, la ICel se clasificó en ICel-I=AQM (100 puntos) e ICel-II cuando fue >100 puntos. Se analizaron dos sumatorias, SumTotal: la suma de AQM+SCSCS+SF y SumIA: AQM+SF. La fertilidad fue de 52,64%, la asociación chi cuadrado con FERT fue significativa (p<0,05) para Finca 1 e ICel-II de SumIA con 74,16% y 61,86% de preñez, respectivamente. La regresión logística de Finca e ICel sobre FERT indicó mayor posibilidad de preñez en vacas de Finca 1 e ICel-II, con valor de la razón de probabilidades (Odds Ratio) de 3,116 (2,025-4,792) e ICel-II-SumIA de 1,746 (1,151-2,648), respectivamente. La calificación de los signos secundarios de la conducta sexual de la vaca asociados a la AQM para establecer la intensidad del celo, puede contribuir a pronosticar la fertilidad en la GDP.
A study was conducted to assess sexual behavior (SB) and estrous intensity (EI) in crossbred dual-purpose livestock (DPL) and its relationship with fertility (FERT) at the time of artificial insemination (AI). Cows reared in two farms (Farm 1 and Farm 2) located in the Tropical Rainforest of Venezuela were used. Five secondary behavioral signs (SBS) were registered; also, the following three physical signs (PS) at AI were registered: reddening of vulvar mucous membrane, mucus discharge and abrasions associated with the main sign of standing estrous (SE). Cows were visually observed four times in daylight, for one hour at three-hour intervals. They were fed on pasture, supplemented with concentrated salts and water ad libitum in pens. The AI was done using the am-pm rule. FERT was measured by transrectal pregnancy diagnosis performed 45-60 d after AI. Each sign observed was assigned a score, being 0 its absence. The SE was assigned a value of 100 points; the EI was ranked as EI-I= SE (100 points) and EI-II, for values >100 points. Two types of sum were analyzed: Total Sum = EI+SBS+PS and AI Sum = SE+PS. The overall fertility was 52.64%, the chi square association test with FERT was statistically significant (p<0.05) for Farm 1 and EI-II in AI Sum, with 74.16% and 61.86% of pregnancy, respectively. The logistic regression of farm and EI on FERT, indicated a greater likelihood of pregnancy for cows in Farm 1 and EI-II, with odds ratio values of 3.116 (2.025 to 4.792) and EI-II- AI Sum of 1,746 (1.151 to 2.648), respectively. The rating of SBS of the cow, associated with SE to set the intensity of the heat can help predict fertility in DPL.
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Con el objetivo de caracterizar la dinámica folicular durante el ciclo estral (CE) en vacas Brahman, fueron evaluados 12 CEs con duración promedio de 21,3 ± 0,7 d (rango=19-24 d). Setenta y cinco porciento (9/12) de los CEs presentaron dos ondas de crecimiento folicular (CF), emergiendo los días 1,6 ± 0,4 y 8,4 ± 0,4 del ciclo, respectivamente. En CEs de una sola onda (2/12), la emergencia ocurrió el día 14,5 ± 0,7; mientras en el CE de tres ondas (1/12), las mismas emergieron los días 2, 10 y 17. Durante el CE ocurrieron cambios en las clases foliculares (Clase 1 [C1]: ≤5 mm; Clase 2 [C2]: 6-9 mm; Clase 3 [C3]: ≥10 mm). Disminuyó el número de folículos C1 mientras aumentó el número de folículos C2 durante el reclutamiento, y descendió el número de folículos C2 mientras aumentó el número de folículos C3 durante la selección. La tasa de crecimiento (TC) fue mayor (P<0,05) para el folículo dominante (FD1= 0,78 ± 0,1 mm/d; FD2=0,40 ± 0,1 mm/d), que en el folículo subordinado (FS1= -0,01 ± 0,1 mm/d; FS2= 0,22 ± 0,1 mm/d). No hubo diferencia en el máximo diámetro alcanzado por el FD (FD1= 12,2 ± 0,4 mm; FD2= 12,7 ± 0,4 mm). El diámetro del cuerpo lúteo (CL) aumentó (fase de crecimiento) hasta alcanzar su máximo tamaño (fase de meseta), disminuyendo hasta sudesaparición (fase de regresión). Los niveles de P4 mostraron correlación positiva con el diámetro del CL (r=0,54; P<0,01), aumentando los niveles de P4 durante la fase de crecimiento del CL y disminuyendo durante su regresión, con poca variación durante la fase de meseta. Estos resultados permiten señalar que la dinámica folicular en vacas Brahman presenta los mismos patrones observados en ganado Bos indicus, previamente reportados.
To characterize the follicular dynamics during the estrous cycle (EC) in Brahman cows, 12 ECs with a mean duration of 21.3 ± 0.7 d (range= 19-24 d), were evaluated. Seventy five percent (9/12) of the ECs had two waves of follicular growth (FG; 20.6+0.5 d), emerging on days 1.6+0.4 and 8.4+0.4, respectively. In ECs of one wave of FG (2/12), emergence occurred on day 14.5+0.7; whereas in ECs with three waves (1/12), waves emerged on days 2, 10 and 17, respectively. During the EC, the number of follicles (Class 1 [C1]= ≤ 5 mm, Class 2 [C2]= 6-9 mm; Class 3 [C3]= ≥ 10 mm) changed, showing a decrease in C1 follicles and an increase in C2 follicles, during the recruitment phase, and a decrease in C2 follicles during the selection phase, with an increase in C3 follicles. The growth rate of the dominant follicle (DF; DF1=0.78 ± 0.1 mm/d; FD2= 0.40 ± 0.1 mm/d) was greater (P<0.05) than the growth rate for subordinate follicles (SF1=-0.01 ± 0.1 mm/d; SF2=0.22 ± 0.1 mm/d). There was no difference in size between DF1 and DF2 (12.2±0.4 vs. 12.7 ± 0.4 mm). From the beginning the diameter of the corpus luteum (CL) increased (growth phase) until it reached the maximum size (plateau phase), to decrease due to its regression. Plasma progesterone (P4) levels showed a positive correlation (r=0.54; P< 0.01) with the diameter of the CL. These results allowed to conclude that the follicular dynamics during the EC in Brahman cows had the same patterns observed in Bos indicus and Bos taurus cattle, previously reported.
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El objetivo del presente trabajo fue evaluar la respuesta de la aplicación doble o triple de prostaglandina sobre la regresión de CL, ovulación y retorno al celo después de un tratamiento superovulatorio en vacas donantes de embriones. Para este experimento se tomaron 44 vacas asignadas al azar a dos grupos de tratamiento. Al primero (n = 23; CLO 0 & 7) se le aplicó una dosis de 500 μg de cloprostenol los días 0 (denominado día de la colecta) y 7; al segundo grupo (n = 21; CLO 0, 1 & 7) se le aplicó una inyección adicional el día 1. Los animales fueron examinados por ultrasonografía los días 0, 4, 7, 10 y 13 para evaluar la regresión de cuerpos lúteos y la ovulación. Se realizó observación del celo dos veces al día (mañana y tarde). El 60,8 y 52,3% de los grupos CLO 0 & 7 y CLO 0, 1 & 7, respectivamente, presentaron signos de celo. No se presentaron diferencias en el día del celo entre los grupos (7,2 ± 0,3, 7,3 ± 0,5 días). Tampoco hubo diferencia para la variable ovulación (8,5 ± 0,9 y 9,8± 0,9 días). Todas las vacas tratadas regresaron los cuerpos lúteos antes de finalizar el experimento. Cuando se analizó el tiempo de ovulación, se encontró que las vacas con 4 o menos cuerpos lúteos ovulan en un tiempo menor (P < 0,01) que las vacas con 5 o más cuerpos lúteos. Se concluye que no hay diferencia entre la doble o triple aplicación de cloprostenol para las variables. Sería innecesaria una aplicación adicional de cloprostenol el día 7.
The purpose of the present study was to evaluate the effect of prostaglandin (PG) treatment schedule on luteal regression and return to estrus in superovulated cows. A group of 44 donor cows were randomly assigned to two groups on the day of ova/ embryo collection (day 0). The first group (n = 23; CLO 0 & 7) was treated with 500 μg of cloprostenol on days 0 and 7 after embryo recovery; the second group (n = 21; CLO 0, 1 & 7) received an additional treatment with cloprostenol on day 1. All animals were scanned by transrectal ultrasonography on days 0 (embryo recovery), 4, 7, 10 and 13 to evaluate CL regression and subsequent ovulation. Estrus detection was done twice daily (am/pm) starting on day 4. There were no significant differences between groups in the percentage of animals returning to estrus (60.8% and 52.3%, respectively), or the intervals from the first PG treatment to estrus (7.2 ± 0.3 vs 7.3 ± 0.5 days), or ovulation (8.5 ± 0.9 vs 9.8± 0.9 days). All cows had luteolysis before the end of the experiment. Animals that had 4 CL or less ovulated earlier than cows that had 5 or more CL (P<0.01). In summary, there was no difference in luteal regression and the return to estrus and ovulation in donor cows treated with cloprostenol twice or three times after superovulation. It would not appear to be necessary to treat donors with PG 7 days later, since all cows had luteal regression after the first PG treatment.
ABSTRACT
Los machos y las hembras ovinas ubicadas en altas latitudes presentan variaciones estacionales en la actividad reproductiva. La actividad sexual de las ovejas es estimulada por la disminución del fotoperiodo, de suerte que los animales que muestran estacionalidad reproductiva pueden disminuir su respuesta al reducirse la latitud. El eje hipotalámico hipofisiario funcional es esencial para la reproducción en mamíferos. El hipotálamo secreta el decapéptido, hormona liberadora de gonadotropinas (GnRH), responsable de iniciar una cascada de eventos que regula las gónadas. Durante el ciclo estral de la oveja, los niveles circulantes de la hormona luteinizante (LH) y de la progesterona (P4) están inversamente relacionados, evidenciando que la P4 podría inhibir la secreción tónica de LH. La P4, de acuerdo con sus efectos, es el esteroide ovárico más importante en las hembras mamíferas y está implicada en la compleja regulación de la función reproductiva. Durante la fase luteal del ciclo estral, la P4, producida por el cuerpo lúteo, inhibe la secreción de la GnRH hipotalámica y, consecuentemente, disminuye la concentración periférica de las gonadotropinas. La fase folicular inicia con la disminución de las concentraciones de P4, ocurrida después de la luteólisis, y es caracterizada por el aumento en la secreción de las gonadotropinas y del estradiol (E2). Esta elevación en el E2 circulante provoca el surgimiento del pico preovulatorio de LH, causado por el abrupto y continuo incremento en la secreción de GnRH. Las mediciones seriadas de E2, P4 y LH al momento de la ovulación en la oveja han demostrado que la secreción máxima del estrógeno desde los folículos preovulatorios precede el surgimiento de la LH. Datos recientes han mostrado que otros esteroides secretados por el folículo preovulatorio pueden actuar sinérgicamente con el estradiol para inducir la ovulación. La presente revisión pretende abordar las relaciones temporales existentes entre la circulación de LH y la secreción de los esteroides ováricos, 17-β estradiol y progesterona, durante el ciclo estral de la oveja.
Ewes and rams from temperate latitudes show seasonal variations in reproductive activity. Sheep sexual activity is stimulated by alterations in the photoperiod, so that animals displaying reproductive seasonality can reduce their response to seasonality as latitude decreases. A functional hypothalamic pituitary axis is essential for mammalian reproduction, since the hypothalamus secretes the decapeptide, gonadotropin-releasing hormone (GnRH) that is responsible for initiating the cascade of events that regulate gonadal function. During the estrous cycle of the ewe, circulating LH and P4 levels are inversely related, thus providing circumstantial evidence that progesterone may inhibit tonic LH secretion. Progesterone (P4), in terms of the cumulative duration of its effects, is the most important ovarian steroid secreted during the lifetime of the female mammal and it’s central to the complex regulation of normal reproductive function. During the luteal phase of the estrous cycle, the P4 produced by the corpus luteum inhibits hypothalamic GnRH secretion, and consequently, peripheral gonadotrophin concentrations are low. The follicular phase, which is initiated by the decline in circulating P4 concentrations after luteolysis, is characterized by increased gonadotrophin and Estradiol (E2) secretion. This rise in circulating E2 induces the preovulatory LH surge, which is caused by a robust, abrupt, and continuous increase in GnRH secretion. Serial measurements of E2, P4 and LH during ovulation time in the ewe have shown that maximum secretion of estrogen from pre-ovulatory follicles precedes the LH surge. Recent data show that other steroids secreted by the pre-ovulatory follicle may act synergistically with oestradiol in inducing ovulation. The present review was undertaken to observe discuss the temporal relationship between circulating LH and the secretion of the ovarian steroids, estradiol 17-β and progesterone, during the oestrous cycle in the ewe.
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A objeto de evaluar el efecto de la condición corporal al parto (CCAP) y del nivel de alimentación (NA) sobre la involución uterina (IU), actividad ovárica (AO), preñez (PR) y expresión de los receptores de leptina (EXPLEP) a nivel hipotalámico y ovárico en vacas postparto, se emplearon 27 vacas mestizas (Bos taurus x Bos indicus). Los animales fueron asignados al azar, con arreglo factorial 2x2, a uno de cuatro tratamientos (T). T1: CCAP baja (<2,5) + NA bajo (BCBA) (n=6); T2: CCAP baja (<2,5) + NA alto (BCAA) (n=7); T3: alta CCAP (>2,5) + bajo NA (ACBA) (n=7) y el T4: CCAP alta (>2,5) + NA alto (ACAA) (n=7). La dieta basal fue de heno de Cynodon nlemfluensis (8% proteína cruda; PC) y un suplemento (23%; PC), a una relación 70:30. Para evaluar IU se consideró: la característica de la secresión uterina (CSU), simetría de los cuernos uterinos (SCU), diámetro cervical (DC) y posición del útero (PU). La evaluación reproductiva se realizó semanalmente desde los 15 hasta los 45 días postparto (DPP), por palpación transrectal, ultrasonografía y progesterona (P4) en plasma. La AO fue evaluada a través de folículos ováricos (F), clasificados en clases: C1 (≤5 mm), C2(6-9 mm) y C3 (≥10 mm) y la presencia de cuerpos lúteos (CL). La PR fue comprobada a través de la palpación rectal, ultrasonido y P4. Cambios metabólicos energéticos fueron medidos, a través del colesterol total (COL) y fructosamina (FRTS) a los 3, 15, 30 y 45 DPP. La expresión hipotalámica y ovárica de los receptores de leptina (EXLEP) fue evaluada mediante la técnica de Western blot, empleando tejidos de 8 vacas sacrificadas a los 45 DPP. Los datos fueron analizados a través de un análisis de regresión multivariado multiple, ANAVAR para medidas repetidas en el tiempo, una regresión múltiple de Cox y una prueba de Kruskal y Wallis. Los resultados muestran correlación (P<0,05) entre T y C3 y entre C3 y CSU a los 22 al 30 DDP. Se obtuvo una correlación entre CL y CSU en el 37 DDP. C1 no estuvo asociado a T ni a IU. Hubo correlación significativa (P<0,01) entre las diferentes variables de IU (CSU, DC, SCU y PU). El análisis de regresión multivariado múltiple detectó efecto significativo (P<0,05) de T y DC sobre AO. La condición corporal postparto (CCPP) afectó AO (P<0,01). Cox para CL dependió (P<0,01) de CSU y SCU. El efecto de T sobre P4 acumulada fue significativa (P<0,01) y CCAP tuvo efecto significativo sobre P4 (P<0,05) desde el 30 DPP. FRTS fue diferente entre T (P<0,05) pero no entre períodos de muestreo. EXLEP para receptores hipotalámicos fue mayor para vacas con alta CCAP, independientemente del NA. PR fue diferente entre T (P<0,01). Valores de PR hasta los 120 DPP fueron: T3: 75%; T4: 60% vs. T2: 0% y T1: 20%. Se concluye que T afectó la IU (CSU, SCU) y la AO (clases foliculares y CL). Se evidenció un efecto de CCAP sobre la expresión de los receptores de leptina en el hipotálamo como uno de los mediadores en la regulación de la actividad ovárica. En consecuencia de lo anterior, hubo una mayor tasa de preñez antes de los 120 DPP, en los tratamientos con mejor CCAP.
Effect of Body Condition at Calving and Feeding Level on Uterine Involution, Ovarian Activity, Pregnancy and the Hypothalamic and Ovarian Expression of Leptin Receptors in Dual Purpose Cows Abstract To evaluate the effect of body condition at calving (BCAC) and different feeding levels (FL) on uterine involution (UI), ovarian activity (OA), pregnancy (PR), and hypothalamic and ovarian leptin receptor expression (LEPEXP) in postpartum cows, twenty seven crossbred cows (Bos taurus x Bos indicus) were randomly assigned in a 2 x 2 factorial design into four treatments (T): T1, low body condition (LBC; < 2.5) + low FL (LBCLFL; n = 6); T2, LBC (< 2.5) + high FL (LBCHFL; n = 7); T3, high BC (> 2.5) + low FL (HBCLFL; n = 7) and; T4, high BC (>2.5) + high FL (HBCHFL; N = 7). Basal diet was made of hay from Cynodon nlemfluensis (11% crude protein, CP) plus supplement (23% CP) at a 70:30 ratio. To assess uterine involution (UI), the following was considered: characteristic of uterine secretion (CUS), uterine horn simmetry (UHS), cervix diameter (CD), and uterine position (UP). Weekly, from 15 to 45 days postpartum (DPP), the reproductive tract was evaluated by transrectal palpation, ultrasonography, and RIA of plasma progesterone (P4). The OA was assessed through the ovarian follicles (OF), which were classified as : C1 (≤ 5 mm), C2 (6-9 mm), C3 (≥ 10 mm); and the presence of corpora lutea (CL). The PR was verified by rectal palpation, ultrasound, and P4. Metabolic changes were measured as total cholesterol (TC) and fructosamine (FRTS) at 3, 15, and 45 DPP. The hypotalamic and ovarian LEPEXP were determined by Western blot from tissue samples of 8 cows slaughtered at 45 DPP. Data were statistically analyzed by multivariate multiple regressions, ANOVA for repeated measurements on time, Coxs multiple regression and a Kruskal and Wallis test. Results show a correlation between T and C3 and between C3 and CUS at 22 and 30 DPP. Also, a correlation was detected between CL and CUS at 37 DPP. No association between C1 and T or C1 and UI was found. The multivariate multiple regressions detected a significant effect (P<0.05) of T and CD on OA. The BCAC influenced OA (P < 0.01). Cox value for CL depended on CUS and UHS (P<0.01). The effect of T and BCAC over accumulated P4 was significant (P<0.05) and BCAC had an effect on P4 from 30 DPP. FRTS was different among T (P<0.05), but were not among sample times. The LEPEXP for hypothalamus was higher for cows with high BCAC, independently from FL. The PR was different among T (P<0.01). Values for PR at 120 DPP were: T3: 75% and T4: 60% vs T2: 0% and T1: 20%. In summary, T, BCAC, CUS and UHS exerted a positive effect on OA. The LEPEXP at the hypothalamus levels corroborated the response of BCAC on OA. Consequently, there was a high pregnancy rate before 120 DPP in T with better BCAC.
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The growth of the follicle and oocyte in the Indian gerbil (Tatera indica) was a continuous process. The relationship between follicle and oocyte or its nucleus was log linear, represented by the equation log Y =a + b log X. A linear relationship (Y = a + bX) existed between the oocyte and its nucleus. The number of stages I and II follicles varied significantly during the oestrous cycle. Maximum percentage of stage I follicles was observed during oestrus and metoestrus, while stage II follicles were abundant during dioestrus, metoestrus and pro-oestrus. These follicles were significantly more in number than other types of the follicles. The occurrence of comparatively larger follicles during pro-oestrus and the presence of newly formed corpora lutea at oestrus, indicated ovulation in the early oestrus.
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The number and affinity of ?-adrenoceptors on rat uterine smooth muscle membranes were determined by radioligand binding technique. The number of ?-adrenoceptors (shown by maximum binding capacity RT) of uterus in proestrus and estrus stage (126.84?54.69 fmol/mg preicin) was significantly higher than those in diestrus and metestrus stage (77.98 + 30.66 fmol/mg protein) (p