Influência do manejo na fisiologia reprodutiva do macho bovino / Influence of management on the reproductive physiology of male bovine / Influencia del manejo en la fisiología reproductiva del bovino macho

O conhecimento da fisiologia do desenvolvimento testicular e ponderal, a precocidade sexual, a capacidade de produção e qualidade espermática, além dos fatores que potencialmente interferem nestes processos, são importantes para predizer a capacidade reprodutiva dos touros. Entre esses fatores, existem alguns que podem influenciar negativamente na fisiologia reprodutiva do touro, e, dessa forma, reduzir a fertilidade desses animais e causar esterilidade, tais como os fatores diretamente relacionados ao manejo e a nutrição. Dessa forma, torna-se de fundamental importância o conhecimento da fisiologia do desenvolvimento testicular e ponderal, e de como alguns fatores, como o manejo e o clima, podem interferir nestes processos. Portanto, o objetivo desta revisão é demonstrar como alguns fatores do ambiente, tais como o manejo e o clima, podem influenciar nessas características, com vistas à produção animal.(AU)

Knowledge of the physiology and weight of the testicular development, sexual precocity, ability and quality of sperm production, and the factors that potentially interfere with these processes are important for predicting the reproductive capacity of bulls. Among these factors, there are some that can negatively influence their reproductive physiology, and thus reduce their fertility, causing sterility, such as factors directly related to the management and nutrition. Thus, it is of fundamental importance to study the physiology of testicular development and weight, and how certain factors, such as management and climate, can interfere with these processes. Therefore, the aim of this review is to show how some environmental factors, such as management and climate, can influence these characteristics, aiming to animal production.(AU)

El conocimiento de la fisiología del desarrollo testicular y ponderal, la precocidad sexual, la capacidad de producción y la calidad del esperma, además de los factores que potencialmente interfieren en estos procesos, son importantes para predecir la capacidad reproductiva de los toros. Entre estos factores, hay algunos que pueden influir negativamente en la fisiología reproductiva del toro, y por lo tanto reducir la fertilidad de esos animales y causar esterilidad, tales como los factores directamente relacionados al manejo y la nutrición. Por lo tanto, es de fundamental importancia el conocimiento de la fisiología del desarrollo testicular y ponderal, y cómo ciertos factores, como el manejo y el clima, pueden interferir en estos procesos. Así, el objetivo de esta revisión es demostrar cómo algunos factores ambientales, tales como manejo y el clima, pueden influenciar en esas características, con miras a la producción animal.(AU)

Morphometry and histomorphometry of the testis in crossbred pigs fed diets with different protein levels / Morfometria e histomorfometria do testículo em suínos híbridos recebendo dietas com diferentes níveis de proteína

Aiming to evaluate the effect of the diet protein content on testicular parameters in pigs, 21 non-gelded male Dalland pigs were used and randomly divided into three groups. Males belonging to groups G2 and G3 received a diet with crude protein levels of 15% below and above, respectively, in relation to G1 (control). At 210 days of age, animals were castrated, and testis and epididymis were collected for morphometric and histomorphometry analyses. No difference was observed in relation to the total length of seminiferous tubules (G1=3239.9±333,3m; G2=2989.4±171,7m and G3=3059.5±254.9m), population of Sertoli cell (G1=4.7±0.5x10(9); G2=4.3±0.3x10(9) and G3=4.7±0.5x10(9)), population (G1=31.6±5.58x10(9); G2=27.3±4.0x10(9) and G3=26.4±3.9x10(9)) and volume of Leydig cells (G1=1289.3±182.6µm³; G2=1179.1±85.4µm³ and G3=1133.3±37.8µm³) and sperm production (G1=5.9±0.9x10(9); G2=5.6±0.6x10(9) and G3=5.1±0.3x10(9)). Protein levels were sufficient to maintain spermatogenesis in different experimental groups. It can be concluded that the magnitude of variation in levels of protein used in different stages of development was not sufficient to promote significant changes in testicular development and spermatogenesis process in adult animals.

Avaliou-se o efeito do teor de proteína da dieta sobre características testiculares em suínos, utilizando-se 21 suínos da raça Dalland, distribuídos aleatoriamente em três grupos. Os animais do G2 e G3 receberam dieta com porcentagens de proteína bruta de 15% para mais e para menos, respectivamente, em relação ao G1 (controle). Aos 210 dias de idade, os animais foram orquiectomizados e os testículos e epidídimos foram coletados para análises morfométricas e histomorfométricas. Observou-se efeito significativo da porcentagem de proteína sobre o comprimento e a largura dos testículos, e nenhuma diferença foi identificada em relação ao comprimento total dos túbulos seminíferos (G1=3239,9±333,3m; G2=2989,4±171,7m e G3=3059,5±254,9m), à população de células de Sertoli (G1=4,7±0,5x10(9); G2=4,3±0,3 x10(9) e G3=4,7±0,5x10(9)), à população (G1=31,6±5,58x10(9); G2=27,3±4,0x10(9) e G3=26,4±3,9x10(9)) e ao volume das células de Leydig (G1=1289,3±182,6µm³; G2=1179,1±85,4µm³ e G3=1133,3±37,8µm³) e à produção espermática (G1=5,9±0,9 x10(9); G2=5,6±0,6x10(9) e G3=5,1±0,3x10(9)). Os percentuais de proteína foram suficientes para a manutenção da espermatogênese nos diferentes grupos. Pode-se concluir que a magnitude da variação dos níveis de proteína usada em diferentes fases do desenvolvimento não foi suficiente para promover alterações significativas no desenvolvimento testicular e no processo espermatogênico em animais adultos.

Testis evaluation of adult Wistar rats after neonatal treatment with fluoxetine / Avaliação testicular de ratos Wistar adultos após tratamento neonatal com fluoxetina

In current assay the serotoninergic system in newly-born Wistar rats underwent pharmacological modification by fluoxetine, a selective serotonin reuptake inhibitor (SSRI), to investigate its repercussion on testicular parameters in adult animals. Thirty animals were distributed according to treatment: control animals (n = 6), animals treated with 1 mg kg-1 (n = 6), 5 mg kg-1 (n = 6), 10 mg kg-1 (n = 6) and 20 mg kg-1 (n = 6) of fluoxetine (IP). When 150 days old, the animals were anesthetized and perfused intra-cardiacally with fixative solution. Testes were routinely processed for inclusion in plastic resin (methacrylate glycol). Further, 4 µm-thick histological sections were stained with toluidine blue/sodium borate 1% and analyzed histometrically. Pharmacological intervention on the serotoninergic system during the postnatal period of the testes development in Wistar rats with fluoxetine chlorohydrate reduced parameters, such as testicular weight, testis liquid weight and seminiferous tubules diameter. However, testicular parameters, such as daily sperm production (DSP), spermatogenesis efficiency (DSP/g/testis) and cell population in stage VII of adult animals, were not influenced by fluoxetine chlorohydrate usage during neonatal period. Results show that administration of fluoxetine during 21 days after birth may induce adverse changes in the spermatogenesis of adult rats.

No presente trabalho, o sistema serotoninérgico de ratos Wistar recém-nascidos foi farmacologicamente modificado por um inibidor seletivo de recaptação da serotonina, fluoxetina, com o objetivo de observar sua repercussão nos parâmetros testiculares em ratos adultos. Trinta animais foram distribuídos de acordo com o tratamento: controle (n = 6), tratado com 1 mg kg-1 (n = 6), 5 mg kg-1 (n = 6), 10 mg kg-1 (n = 6) e 20 mg kg-1 (n = 6) de fluoxetina. Aos 150 dias de vida, os animais foram anestesiados e perfundidos intracardiacamente com solução fixadora. Os testículos foram removidos e processados para inclusão em resina plástica (glicol metacrilato). Cortes histológicos com 4 µm de espessura foram corados por azul de toluidina/borato de sódio 1% e analisados histometricamente. O tratamento com fluoxetina reduziu nos parâmetros de peso testicular líquido e bruto, bem como no diâmetro dos túbulos seminíferos. Entretanto, os parâmetros testiculares de produção espermática diária (PED), eficiência espermática (PED/g/testículo) e população de células germinativas no estágio VII não estavam alteradas pelo tratamento com fluoxetina. Em conclusão, a administração de fluoxetina durante 21 dias após o nascimento pode induzir efeitos adversos na espermatogênese de ratos adultos.

Toxicological screening of Mikania glomerata Spreng., Asteraceae, extract in male Wistar rats reproductive system, sperm production and testosterone level after chronic treatment / Triagem toxocológica do extrato de Mikania glomerata Spreng., Asteraceae, no sistema reprodutor, produção espermática e nível de testosterona em machos de ratos Wistar após tratamento crônico

Some compounds present in therapeutic plants may be responsible for the occurrence of adverse side effects. Coumarin and flavonoids are substances found in many plant species that showed antifertility activity in female rats and dogs, respectively. Mikania glomerata Spreng., Asteraceae, known as guaco in Brazil, is a plant largely used in folk medicine and its leaves are reported to have coumarin and flavonoids. This work analyzes the effect of chronic administration of M. glomerata on the reproductive system of male rats. Thirty-day-old Wistar rats were treated with M. glomerata hydroalcoholic extract at a dose of 3.3 g/kg of body weight for ninety days. Body and organ weights, gamete concentration on the epididymis cauda, serum testosterone level and food consumption were evaluated. No significant alteration was observed in any of the variables analyzed, suggesting the absence of toxic action or antifertility activity of the M. glomerata hydroalcoholic extract.

As plantas medicinais podem apresentar na sua constituição compostos capazes de causar efeitos adversos no organismo. Cumarina e flavonoides são substâncias encontradas em muitas espécies vegetais, cuja interferência na fertilidade de ratas e cadelas, respectivamente, foi evidenciada em estudos prévios. Mikania glomerata Spreng., Asteraceae, (guaco) é uma planta usada no tratamento de doenças respiratórias e em suas folhas foi detectada a presença de cumarina e flavonoides. Neste estudo, avaliou-se o efeito do extrato hidroalcoólico, preparado com partes aéreas de guaco, no sistema reprodutor de ratos submetidos a tratamento crônico. Ratos Wistar (trinta dias de idade) foram tratados com extrato hidroalcoólico de guaco na dose de 3,3 g/kg de peso corporal durante noventa dias. O peso corporal e de órgãos, a produção de espermatozoides, a concentração de testosterona plasmática e o consumo de ração foram avaliados. Não foi observada nenhuma alteração significativa das variáveis analisadas e o tratamento não afetou o consumo de ração. Estes dados sugerem que, na dose utilizada, o extrato hidroalcoólico de guaco não teve efeito tóxico e nem interferiu com a fertilidade de ratos Wistar submetidos a um tratamento de longa duração.

The effects of Tynnanthus fasciculatus (Bignoniaceae) infusion on testicular parenchyma of adult Wistar rats

Traditional medicine provides strong guidance for scientific experiments involving plant products used by the Brazilian people. The species "cipó-cravo" (Tynnanthus fasciculatus) is a plant commonly used either to combat indigestion and stomachaches, or as a general stimulant and aphrodisiac. In this study, the effects of "cipó-cravo" infusion were investigated within the testicular parenchyma of adult Wistar rats. Rats were divided into 3 groups: a control (distilled water) and two treated groups, which received the plant infusion (100 and 200mg/animal/day). The 200mg dose promoted a significant increase of the testicular parenchyma weight and of the volume and total length of the seminiferous tubules, as well as in total daily sperm production and sperm production per gram of testis.

Efecto del coumestrol sobre la producción espermática y la conducta de exploración olfatoria de perros estimulados con moco vaginal estral / Effect of coumestrol on sperm production and smell exploratory behavior in dogs stimulated with vaginal mucus

Dog overpopulation is a major health problem in developing countries due to the existence of some zoonotic diseases in which dogs act as reservoirs, besides the aggressive events to humans. Distribution, behavior patterns and combined methodologies are needed aspects in the design of successful dog population control programs. Coumestrol is a phytoestrogen which induces alterations in the reproductive male system, when bind to alpha and beta estrogen receptors acting as an agonist or antagonist fashion. Both receptor types also exist in central nerve regions governing sexual behavior of those animals such as the preoptic area, ventro medial nucleous, the amygdala and the olfactory bulb. In this study, 300 μg/kg coumestrol was orally administered to male dogs, once a week for a 4 week period. Dogs were freed for 5 min in a 9 m² area having a recipient containing vaginal discharges from estrous dog females and other similar vessel containing sterile saline solution. Smelling latency time for each recipient, smelling frequency and territory marking in response to stimulus, was recorded. At the end of the test, semen was collected and evaluated. A significative difference (P < 0.005) in smelling latency time and smelling frequency to the vaginal discharge was found; sperm count decreased from 518.4 ± 215.4 × 10(6) to 57.6 ± 50.4 × 10(6) at week 4 and the abnormal sperm morphology increased from 14.7 ± 3.3% at 0 week to 60.0 ± 20%. In conclusion, 300 μg/kg coumestrol given orally to male dogs for 4 weeks induces alterations in the olfactory behavior along with an oligo and teratospermic effect.

La sobrepoblación canina es un problema importante de salud pública debido a la transmisión de enfermedades zoonóticas y las agresiones hacia el humano. En el diseño de programas para controlar la población canina se requiere del conocimiento de su distribución, comportamiento y metodologías combinadas para tener éxito. El coumestrol es un fitoestrógeno que induce alteraciones en el aparato reproductor de los machos al unirse a los receptores estrogénicos alfa y beta, en donde actúa de manera dosis-dependiente como agonista o antagonista. Estos receptores también existen en las estructuras del sistema nervioso que regulan el comportamiento sexual, como la región preóptica, núcleo ventromedial, la amígdala y el bulbo olfatorio. En este estudio se administró coumestrol (300 μg/kg) por vía oral a perros machos, una vez por semana durante cuatro semanas; los perros se colocaron durante cinco minutos en un área aislada de 9 m² en donde se colocó un frasco conteniendo secreciones vaginales obtenidas de perras en estro y otro con solución salina estéril. Se registró el tiempo de latencia de los perros para olfatear cada frasco, su frecuencia de respuesta y la frecuencia con que se presentó conducta de marcaje en respuesta al estímulo. Una vez concluido el experimento, se obtuvo semen y se evaluó. Se encontró diferencia significativa (P < 0.005) en el periodo de latencia y frecuencia con la que el macho se acercó a oler las secreciones vaginales y el conteo espermático disminuyó de 518.4 ± 215.4 × 10(6) al inicio del estudio a 57.6 ± 50.4 × 10(6) en la semana cuatro y el porcentaje de anormalidades espermáticas aumentó de 14.7 ± 3.3 puntos en la semana 0 a 60.0 ± 20.0% en la semana cuatro. Se concluye que el tratamiento de perros con coumestrol durante cuatro semanas ocasiona alteraciones en la conducta de exploración olfatoria y tiene un efecto oligospérmico y teratospérmico.

Efeito do uso de pentoxifilina no período neonatal sobre a produção espermática em ratos Wistar adultos / Effect of pentoxifylline during neonatal period on spermatic production in adult Wistar rats

Utilizaram-se doses crescentes de pentoxifilina em ratos Wistar neonatos visando aumentar a produção espermática em animais adultos. Trinta e sete animais foram distribuídos de acordo com os tratamentos: não tratados (n=10) e tratados com 1mg/kg (n=10), 5mg/kg (n=9) e 10mg/kg (n=8) de pentoxifilina (IP). Aos 90 dias, os animais foram anestesiados e perfundidos intracardiacamente com solução fixadora. Os testículos foram processados rotineiramente para inclusão em resina plástica à base de glicol metacrilato. Cortes histológicos de 4µm de espessura foram corados em azul de toluidina/borato de sódio a 1 por cento e analisados histometricamente. O número de células de Sertoli por secção transversal diminuiu nos grupos tratados com 5mg/kg e 10mg/kg em relação aos grupos controle e tratado com 1mg/kg. O índice de células de Sertoli aumentou nos animais tratados com 5mg/kg em comparação aos do grupo-controle. A utilização da pentoxifilina não foi capaz de induzir aumento na população das células de Sertoli e produção espermática em ratos adultos.

Increasing doses of pentoxifylline were administrated to newborn Wistar rats in order to augment Sertoli cell number and sperm production in the adult rats. Thirty-seven neonate Wistar rats were distributed in four groups: control (n=10) and treated with 1mg/kg (n=10), 5mg/kg (n=9), and 10mg/kg (n=8) of pentoxifylline. At 90 days, the animals were submitted to anesthesia and intracardiac perfusion. Testes were colleted and routinely processed for inclusion in plastic resin with glycol methacrylate. Histological sections (4µm) were stained in toluidine blue/sodium borate (1 percent) and analyzed. Number of Sertoli cell per transversal section of seminiferous tubule had significant reduction in the groups treated with 5mg/kg and 10mg/kg of pentoxifylline as compared to control and the group that received 1mg/kg (P<0.05). The Sertoli cell index significantly increased in the group treated with 5mg/kg compared to control group. Pentoxifylline did not cause increase in the number of Sertoli cells and daily sperm production in adult male rats.

Preliminary assessment of Rosmarinus officinalis toxicity on male Wistar rats' organs and reproductive system / Avaliação preliminar da toxicidade de Rosmarinus officinalis no sistema reprodutor e em órgãos de ratos Wistar

Rosemary (Rosmarinus officinalis L. - Lamiaceae) is a shrub used in the treatment of hepatic, intestinal, renal and respiratory affections. Its toxicity was assessed in female rats and an anti-implantation effect was reported after treatment with this plant. This work analyzes the effect of the short-term administration of R. officinalis extract on vital organs, on the organs of the reproductive system and sperm production of mature male Wistar rats. Adult Wistar rats were treated with 1 mL of R. officinalis aqueous extract at a dose level of 291.2 mg and 582.4 mg/kg of body weight for five days. Body and organs weights, sperm production and food consumption were evaluated. The results showed that the lower dose administration of R. officinalis extract did not significantly alter body and organs weight nor did it interfere with gamete production. However, animals treated with the higher dose showed significant weight increase of the seminal vesicle but no significant alteration of the other variables. Food intake was not affected by the treatments.

Alecrim (Rosmarinus officinalis L. - Lamiaceae) é uma planta utilizada no tratamento de afecções hepática, intestinal, renal e respiratória. Sua toxicidade foi investigada em ratas e seu efeito antiimplantação foi relatado em estudos prévios. Este trabalho analisa o efeito da administração aguda do extrato de R. officinalis em órgãos vitais, em órgãos do sistema reprodutor e na produção de espermatozóides de ratos Wistar adultos. Ratos Wistar foram tratados com 1 mL do extrato aquoso de R. officinalis na dose de 291,2 mg e 582,4 mg/kg de peso corporal por cinco dias. O peso corporal e de órgãos, a produção de espermatozóides e o consumo de ração foram avaliados. Os resultados mostraram que a administração da dose menor do extrato de R. officinalis não alterou significativamente o peso corporal e de órgãos e nem interferiu com a produção de gametas. Entretanto, os animais tratados com a maior dose evidenciaram aumento significativo de peso de vesícula seminal, mas nenhuma outra alteração significativa das outras variáveis. O consumo de ração não foi afetado pelos tratamentos.

Evaluation of Short-term Exposure to Rosmarinus officinalis on Male Swiss Mice's Organs and Reproductive System

Rosemary (Rosmarinus officinalis L. - Labiatae) is a plant in the treatment of urinary disorders, dysmenorhea and respiratory problems. Rosemary toxicity was evaluated in famale rats and an anti-implantation effect was reported after treatment with an aqueous extract of this plant. This works analyzes the effect of a short-term administration of R. officinalis aqueous extract on vital organs, on the organs of the reproductive system and sperm concentration of mature male Swiss mice. Treated animals received 260 mg/kg of body weight for five days. Body and organs weights, sperm production and food consumption were evaluated. This preliminary investigation reports that no body weight reduction and no toxic effect on the organd, gamete production or food intake were detected in any of the groups analyzed, given the experimental protocol used.

Avaliação do efeito de mikania glomerata sobre o sistema reprodutor e órgaõs de ratos wistar submetidos a tratamento subagudo / Short-term exposure to mikania glomerata on male wistar rats' organs and reproductive system

Mikania glomerata (guaco) is a plant well known in Brazil for its therapeutic properties, especially in the treatament of respiratory diseases. Coumarin and flavonoids are active compounds of M. glomerata leaves and have been reported to cause adverse effects on the organism, including antifertility activity in famale rat and male dog respectively. This work analyzes the effect of short-term administration of M.glomerata hydroalcoholic extract on vital organs, of the reproductive system and sperm concentration of mature male wistar rats. Treated animals received 1 ml of the extract at a dose of 1.1 g/kg of body weight for live days. Body and organs weights, sperm production and food consumption were evaluated. No body weigth reduction and no toxic effect on the organs, gamete production or food intake were detected in any of the groups analyzed, given the experimental protocol used.

Continuous Exposure of Lactating Rat Mothers to Polychlorinated Biphenyls (PCBs) Increases Testis Volume, Sperm Production and Sertoli Cell Numbers in Adult Male Offspring / 체질인류학회지

Despite the possible consequences of maternal ingestion of polychlorinated biphenyls (PCBs) on future generation, information in limited on how/whether maternal PCB exposure affects testis of the adult male offspring. Therefore, we conducted two experiments to investigate the effects of intermittent and continuous of lactating rats to low and high doses of Aroclor 1242 (a PCB congener) on volume density of seminiferous tubules and interstitium, testis volume, sperm production/day and the total number of Sertoli cells per testis in adult male offspring. In experiment I, 3 groups of lactating Sprague Dawley rats received daily subcutaneous injections of 0.1 ml of corn oil, low dose (8microgram) and high dose (80microgram) of Aroclor 1242 in corn oil respectively, from parturition to weaning of pups at 21 days. In experiment II, 3 groups of lactating rats received 2 subcutaneous injections per week of 0.1 ml corn oil, low and high doses of Aroclor respectively, as in experiment I. Pups in all groups were weaned at day 21 and were raised on a normal diet until sacrificed at 90 days to evaluate volume density of seminiferous tubules and interstitium, testis volume, sperm production/day and the total number of Sertoli cells per testis. Volume density of seminiferous tubules and interstitium per testis was determined by point counting method. Testis volume and sperm production/day was measured by routine techniques. The total number of Sertoli cells per testis was determined by morphometry(disector method). In experiment I and II, the volume density of seminiferous tubules and interstitium per testis was equal in control and treated testes. In experiment I (continuous exposure), the testis volume was increased by 14.8% (low dose)~16.5% (high dose), and sperm production/day and Sertoli cell numbers were increased 20.4~25%, and 32.6~39.4%, respectively. In experiment II (intermittent exposure), testis volume, sperm production/day and the total number of Sertoli cells per testis were not significantly different (p>0.05) in PCB-exposed rats (both low and high doses) compared to controls. It is clear that continuous exposure, but not intermittent exposure of male rats to Aroclor during the neonatalprepubertal period causes detrimental effects on the testis in adult male offspring. These results emphasize the susceptibility of the developing testis to environmental factors during the crucial neonatal period.

Estimation of daily sperm production in rats and monkeys.

Daily sperm production in rats and monkeys were estimated by extended histometric method. Individual seminiferous tubules were separated, fixed, processed and embedded. Semi-thin sections were stained with toluidine blue and the different cell types quantitated with Chalkley's eye piece. The daily sperm production estimated was compared with that obtained by the homogenization method. The results indicate that daily sperm production obtained by both the methods were comparable. The present histometric method has an added advantage of requiring very small amount of biopsy material to give precise daily sperm production estimations.