RESUMO
Exposure of the fish to a long photoperiod (16L/8D) during the prespawning period accentuates the development of the ovary and increases the secretory activity of the pituitary gonadotrophs (GtH cells). A short photoperiod (8L/16D) or total darkness brings about follicular atresia of the vitellogenic oocytes and inhibits secretory activity of the GtH cells. Both the vitellogenesis and the GtH cell activity are restored in the fish exposed to short photoperiod if it is followed by a long photoperiod. Results indicate that the photoperiod plays a major role in controlling the reproductive activity in the teleost, Puntius sarana.
Assuntos
Peixes/fisiologia , Gonadotropinas/metabolismo , Luz , Ovário/fisiologia , Periodicidade , Hipófise/fisiologia , Animais , Núcleo Celular/fisiologia , Citoplasma/fisiologia , Feminino , Gonadotropinas Hipofisárias/metabolismo , Oócitos/fisiologia , Ovário/anatomia & histologia , Ovário/crescimento & desenvolvimento , Hipófise/metabolismo , Fatores de Tempo , Membrana Vitelina/fisiologiaAssuntos
17-Hidroxiesteroide Desidrogenases/isolamento & purificação , 3-Hidroxiesteroide Desidrogenases/isolamento & purificação , Di-Hidrolipoamida Desidrogenase/isolamento & purificação , Epididimo/enzimologia , Glucosefosfato Desidrogenase/isolamento & purificação , Camundongos/metabolismo , Testículo/enzimologia , Animais , Células Intersticiais do Testículo/enzimologia , Masculino , Especificidade da Espécie , Espermatozoides/enzimologiaRESUMO
Adult individuals of M. platythrix were maintained on 30 per cent D2O by volume in drinking water at varying periods of time. Qualitative and quantitative changes in pituitary FSH and LH cells were observed. The former revealed hyperplasia and hypertrophy by 10 days attaining their peak of activity and hyalinization by 20 days. In contrast response in the LH cells was rather slow. They showed a significant increase in number after 30 days and hyalinization by 50 days. FSH cells revealed decline in activity by 50 days whereas LH cells attained their peak numerically by 40 days and underwent no change thereafter. These observations suggest that in the adult male D2O reveals: 1. hyperactive influence on the gonadotrophs, and 2. differential in FSH and LH secreting cells.
