Binding of 125I-labelled FSH in the mouse testis in vitro

Abstract

In vitro testicular binding of highly purified pituitary FSH [follicle stimulating hormone], labeled by a method which did not significantly affect biological potency, was hormone-specific, tissue-specific and dose-dependent. Hypophysectomy of mice was followed by a progressive increase in the amount of 125I-labeled FSH per unit weight of testis but not in the total amount of hormone taken up the testis. Maximum binding occurred at 4 h in a membrane-containing fraction prepared by high-speed ultracentrifugation of testicular homogenate. This is considerably later than was reported for testicular tissue incubated in vitro at 37.degree. C.