THE QUANTITATIVE DETERMINATION OF FOLLICLE STIMULATING AND LUTEINIZING HORMONES IN MAMMALIAN PITUITARIES AND A DISCUSSION OF THE GONADOTROPIC QUOTIENT, F⁄L1

Abstract

The methods of assaying gonadotrophic substances on the immature [female] rat are submitted to a critical analysis, which leads to the distinction of 4 different rat units. Of these the rat vagina unit (RvU) is found to be the most adequate measure for follicle stimulating hormones. The total amt. of the sample to be tested is administered in 6 injs. in the course of 3 days and the rat is killed 24 hrs. after the last inj. The minimal amt. required to produce cornification (stage 3) in the vaginal epithelium represents the unit value of the prep. A strictly specific test for the luteinizing hormones is found in the activation of the melanophores in the feather germs of African weaver finches. The total dose of gonadotrophic substance is administered in 2 injs. in the breast muscle on consecutive days. The appearance of a black dot or bar on an otherwise white abdominal feather indicates the positive reaction. The minimal required dose is the weaver finch unit (WfU). In dividing RvU by WfU one obtains a gonadotrophic quotient which characterizes the proportion of FH and LH in any given preps. The comparison of 9 mammalian spp. proves that the content in FH is much more variable than that in LH. Beef hypophysis is relatively the poorest and human hypophysis the richest in FH among the assayed spp.