The effects of letrozole-induced maternal hyperandrogenism on sexual behaviors, testicular histology, and serum biochemical traits in male offspring rats: An experimental study.

Background: Intrauterine endocrine abnormalities have profound effects on the development of physiological disorders. Objective: This study aimed to assess the effects of in utero exposure to letrozole (an aromatase inhibitor) and its late consequences on the reproductive and metabolic performance of an adult male offspring. Materials and Methods: 15 pregnant Sprague-Dawley rats (8 wk, 155 gr) were randomly assigned into 5 experimental groups (n = 3/each) and orally received either letrozole at doses of 0.25, 0.75, 1.00, and 1.25 mg/kg body weight (BW) or vehicle (control) on the gestation days of 16, 17, and 18. Pregnancy outcome, sexual behaviors on postnatal day 60, serum biochemical features, and the histopathology of testes were assessed in male offspring. Results: Compared to control group, delayed labor (21.83 vs. 24.25, p < 0.0001) and reduced litter size (n = 12.25 vs. n = 2, p < 0.0001) were recorded in 1.25 mg/kg BW group. A reduction in high-density lipoprotein level and the elevation of testes weight, BW gain, anogenital distance, as well as the serum concentrations of testosterone, triglycerides, cholesterol, and glucose were observed in 1.25 mg/kg BW (p < 0.0001) and 1.00 mg/kg BW (p < 0.0001) groups in comparison to control. A larger number of anogenital female sniffing, pursuit, and mounting behaviors were also observed in 1.25 mg/kg BW group in comparison to control (p < 0.0001). Severe testicular defects including necrosis and disruption of the epithelium of seminiferous tubules, sloughing of epithelial cells, and spermatogenesis arrest were observed in letrozole-treated groups, in a dose-dependent manner. Conclusion: Maternal exposure to letrozole can adversely affect the reproductive and metabolic performance of male offspring rats, suggesting an incomplete sex differentiation.

Association of open field behavior with blood and semen characteristics in roosters: an alternative animal model / Asociación entre la conducta de gallos en campo abierto con sus características de sangre y de semen: un modelo animal alternativo

Introduction. The paucity of literature is addressed regarding the correlation between open field as an individual behavioral trait on reproductive capacity in animals. Materials and methods. To address this, Nine-month-old indigenous roosters were housed in individual cages. Each animal was observed twice a week for ten minutes before feeding in an open field apparatus for two weeks (7:00-12:00PM). Results. Interestingly, it was found that rooster's semen characteristics were correlated with their open field behavior. On the other hand, plasma glucose level as a blood attribute was more correlated with semen characteristics. The open field monitoring also revealed that the roosters with the lowest delay to their first pace had the highest sperm forward motility and lower sperm abnormality. The heterophil to lymphocyte ratio (H:L) was found to be low when pace bout and pace numbers were 20 and 35, respectively. The negative correlation between H:L ratio and semen characteristics (live sperm percentage, sperm concentration, and membrane integrity) may be an indication of poor reproductive performance in fearful roosters with higher H:L ratio. Conclusions. The data suggested a relationship between open field behavior indices and some reproductive parameters in roosters. The results might be applicable for selection of more reproductive animals. Hence, the rooster may also be useful model for similar studies in other species

Introducción. Existe poca literatura que analice la relación entre el comportamiento individual en animales en campo abierto y su capacidad reproductiva. Material y métodos. Para cubrir esta laguna se trabajó con gallos de 9 meses de edad que fueron encerrados en jaulas individuales. Cada animal se observó 2 veces a la semana, durante 10min, en una zona de campo abierto durante 2 semanas, antes de la alimentación (07:00-12:00 p.m.). Resultados. Curiosamente, se encontró que la característica del semen de los gallos se correlacionaba con su comportamiento en campo abierto. Por otro lado, el nivel de glucosa en plasma, como un atributo de la sangre, se correlacionaba con las características del semen. La monitorización en campo abierto también reveló que los gallos con la menor demora en su primer canto tuvieron la mayor motilidad de los espermatozoides y la menor alteración del esperma. El nivel más bajo de la relación entre heterófilos y linfocitos (H: L) fue encontrado cuando los números de cantos y el ritmo eran 20 y 35, respectivamente. La correlación negativa entre el índice H:L y las características del semen (porcentaje de espermatozoides vivos, concentración de espermatozoides, e integridad de la membrana) puede ser un indicio de mal desempeño reproductivo de gallos con mayor índice H:L. Conclusiones. Los datos indican que existe relación entre los índices de comportamiento en campo abierto y algunos parámetros reproductivos de los gallos. Los resultados podrían ser aplicables para la selección de los animales más reproductivos. El gallo también puede ser útil como un modelo para estudios similares en otras especies

Decreased Expression of Arginine-Phenylalanine-Amide-Related Peptide-3 Gene in Dorsomedial Hypothalamic Nucleus of Constant Light Exposure Model of Polycystic Ovarian Syndrome.

BACKGROUND: An abnormality in pulse amplitude and frequency of gonadotropin releasing hormone (GnRH) secretion is the most characteristics of polycystic ovarian syndrome (PCOS). On the other hand, arginine-phenylalanine-amide (RFamide)-related peptide-3 (RFRP3) inhibits the secretion of GnRH in mammalian hypothalamus. The current study performed in order to investigate the expression of RFRP3 mRNA in the dorsomedial hypothalamic nucleus (DMH) after the induction of PCOS in a rat model of constant light exposure, and the possible role of parity on occurrence of PCOS. MATERIALS AND METHODS: In the experimental study, female nulliparous (n=12) and primiparous (n=12) rats were randomly subdivided into control and PCOS subgroups (n=6). PCOS were induced by 90 days exposure to constant light. After 90 days, blood, brain, and ovaries were sampled. Serum levels of follicle stimulating hormone (FSH), luteinizing hormone (LH), and testosterone were evaluated. In addition, six adult female ovariectomized rats as a control of real-time polymerase chain reaction (PCR) tests were prepared and in the DMH of all rats, the relative mRNA expression of RFRP3 was assessed. RESULTS: Histological evaluation of ovaries represented the polycystic features. In addition, serum concentrations of testosterone in the PCOS subgroups were more than the controls (P<0.05). Furthermore, the relative expression of RFRP3 mRNA in PCOS subgroups was lower than the controls (P<0.05). CONCLUSION: Constant light model of the PCOS-induced rats decreased the gene expression of RFRP3 in the DMH that suggests the decrease of RFRP3 may reduce its inhibitory effect on GnRH during the PCOS pathogenesis. This effect was stronger in the nulliparous rats than the primiparous.