RESUMO
In this work, the seric and hypophysial concentrations of the hormones alpha-melantopin and prolactin of male specimens of Leptodactylus ocellatus from the province of Cordoba are studied during a complete annual period. This amphibian presents a continuous reproductive cycle with a wave of greater spermatogenic activity in early summer months (December-January). The results corresponding to hormones show a very similar pattern: both present their maximal seric value in the December-January period, coincidently with the greatest spermatogenic wave. Maximal hypophysial values precede seric concentration maximum by two months. Although the influence of these hormones on amphibian spermatogenesis is not well understood, the observations here described would indicate that alpha-melanotropin as well as prolactin could play a role in the spermatogenic process in Leptodactylus ocellatus.
Assuntos
Prolactina/sangue , Reprodução/fisiologia , Espermatogênese/fisiologia , alfa-MSH/sangue , Anfíbios/fisiologia , Animais , Argentina , MasculinoRESUMO
In this work, the seric and hypophysial concentrations of the hormones alpha-melantopin and prolactin of male specimens of Leptodactylus ocellatus from the province of Cordoba are studied during a complete annual period. This amphibian presents a continuous reproductive cycle with a wave of greater spermatogenic activity in early summer months (December-January). The results corresponding to hormones show a very similar pattern: both present their maximal seric value in the December-January period, coincidently with the greatest spermatogenic wave. Maximal hypophysial values precede seric concentration maximum by two months. Although the influence of these hormones on amphibian spermatogenesis is not well understood, the observations here described would indicate that alpha-melanotropin as well as prolactin could play a role in the spermatogenic process in Leptodactylus ocellatus.
RESUMO
Given the importance of the hormones prolactin and alpha-melanotrophin in the regulation of the mammalian reproductive cycle, it was decided to assess their serum levels during the reproductive cycle of Columba livia (domestic pigeon). Female pigeons were utilized in the stages of egg-laying, incubation and rearing. Simultaneously, the structural changes of the ovary in the aforementioned periods were studied. The levels of prolactin and alpha-melanotrophin showed similar behaviour. The low concentrations found in the period of egg-laying (x +/- s = 4.3 +/- 0.6; 3.5 +/- 0.26 ng/ml) increased significantly during incubation (x +/- s = 6.5 +/- 0.7 ng/ml; 6.6 +/- 1.7 ng/ml) to reach the maximum value in the rearing period (x +/- s = 10.33 +/- 1.8 ng/ml; 13.6 +/- 1.9 ng/ml). Accompanying these changes a marked predominance of the medullary zone over the cortex and lack of developing follicles were found in the rearing state.
Assuntos
Columbidae/sangue , Ovário/anatomia & histologia , Prolactina/sangue , Reprodução , alfa-MSH/sangue , Animais , Columbidae/fisiologia , Feminino , Prolactina/metabolismo , alfa-MSH/metabolismoRESUMO
Given the importance of the hormones prolactin and alpha-melanotrophin in the regulation of the mammalian reproductive cycle, it was decided to assess their serum levels during the reproductive cycle of Columba livia (domestic pigeon). Female pigeons were utilized in the stages of egg-laying, incubation and rearing. Simultaneously, the structural changes of the ovary in the aforementioned periods were studied. The levels of prolactin and alpha-melanotrophin showed similar behaviour. The low concentrations found in the period of egg-laying (x +/- s = 4.3 +/- 0.6; 3.5 +/- 0.26 ng/ml) increased significantly during incubation (x +/- s = 6.5 +/- 0.7 ng/ml; 6.6 +/- 1.7 ng/ml) to reach the maximum value in the rearing period (x +/- s = 10.33 +/- 1.8 ng/ml; 13.6 +/- 1.9 ng/ml). Accompanying these changes a marked predominance of the medullary zone over the cortex and lack of developing follicles were found in the rearing state.
RESUMO
Given the importance of the hormones prolactin and alpha-melanotrophin in the regulation of the mammalian reproductive cycle, it was decided to assess their serum levels during the reproductive cycle of Columba livia (domestic pigeon). Female pigeons were utilized in the stages of egg-laying, incubation and rearing. Simultaneously, the structural changes of the ovary in the aforementioned periods were studied. The levels of prolactin and alpha-melanotrophin showed similar behaviour. The low concentrations found in the period of egg-laying (x +/- s = 4.3 +/- 0.6; 3.5 +/- 0.26 ng/ml) increased significantly during incubation (x +/- s = 6.5 +/- 0.7 ng/ml; 6.6 +/- 1.7 ng/ml) to reach the maximum value in the rearing period (x +/- s = 10.33 +/- 1.8 ng/ml; 13.6 +/- 1.9 ng/ml). Accompanying these changes a marked predominance of the medullary zone over the cortex and lack of developing follicles were found in the rearing state.