Annual changes in the binding of follicle-stimulating hormone to gonads and plasma gonadotropin concentrations in Indian weaver birds inhabiting the subtropical zone

Kazuyoshi Tsutsui*, Seiichiro Kawashima, R. N. Saxena, Susumu Ishii

*この研究の対応する著者

研究成果: Article査読

11 被引用数 (Scopus)

抄録

In birds, annual changes in gonadal weight are much more pronounced in the male than in the female. To analyze the mechanism inducing such a sex difference in the gonadal responsiveness to natural environmental conditions, we measured annual changes in the binding of follicle-stimulating hormone (FSH) to the gonads and the plasma gonadotropin concentration in adult Indian weaver birds inhabiting the subtropical zone. The binding of FSH was highly specific for mammalian FSHs and located primarily in the gonad. The testicular weight and FSH binding showed marked changes during the annual breeding cycle. The testicular weight was maximal in the breeding phase (June, 1987) and minimal in the nonbreeding phase (December, 1987). FSH binding per unit testicular weight was-greatest in the nonbreeding phase, while the total FSH binding per two testes was maximal in the breeding phase and minimal in the regressive phase (October, 1987). In contrast, the changes in the ovarian weight and FSH binding to the ovary were less pronounced than those in the testis. Although FSH binding per unit ovarian weight showed a peak in the nonbreeding phase; there was no significant change in the total FSH binding per ovary during the year, indicating the presence of a clear sex difference in the total FSH binding. Scatchard plot analyses of the binding suggested that the dissociation constant (Kd) ranged from 0.35 to 1.53 nM regardless of sex and season and that the changes in FSH binding were due to changes in the number of binding sites. Plasma FSH and luteinizing hormone (LH) levels markedly changed during the year in both sexes. Both FSH and LH levels were maximal in the breeding phase and minimal in the nonbreeding phase regardless of sex, although. the rate of change in either hormone tended to be greater in the male than in the female.

本文言語English
ページ(範囲)444-453
ページ数10
ジャーナルGeneral and Comparative Endocrinology
88
3
DOI
出版ステータスPublished - 1992
外部発表はい

ASJC Scopus subject areas

  • 内分泌学

フィンガープリント

「Annual changes in the binding of follicle-stimulating hormone to gonads and plasma gonadotropin concentrations in Indian weaver birds inhabiting the subtropical zone」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

引用スタイル