Effect of Pituitary Extracts on the Spermatogenesis of the Green Frog Rana Hexadactyla Lesson
1972 年 19 巻 1 号 p. 59-67
詳細
1972 年 19 巻 1 号 p. 59-67
Hypophysial gonadotropin secretion varies in several Salientia inhabiting temperate climates and the sexual cycle in those animals has been correlated accordingly. In experiments conducted on male Rana hexadactyla, a tropical frog with a continuous spermatogenetic cycle, we studied the relation of the hypophysio-gonadal axis to seasons. Pituitary extracts from animals of the summer or winter months were administered to summer or winter frogs and vice-versa. The effects of the extracts were observed on the spermatogenetic cycle of this species. Spermatogenesis was usually accelerated by pituitary extract administered at any time of the year, although the effect was more pronounced in frogs treated with summer pituitary extracts during summer-time than in winter. The probable significance of the results obtained in relation to hypophysial gonadotropin secretion and to the sensitivity of the germinal epithelium of Rana hexadactyla is discussed.
