Effect of Purified Gonadotropins upon Release of Spermatozoa in the Frog, Rana pipiens

Abstract
Release of spermatozoa by the frog, Rana pipiens, after giving purified follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin and human chorionic gonadotropin (HCG) was studied. Minimal doses of these hormones which produced a response in over 75% of the animals in each group were 5 mg of FSH, 0.05 mg of LH and 25 I. U. of HCG. Prolactin did not elicit a response. Our data indicate that the release of spermatozoa in the frog can be induced by LH or a substance with an LH-like activity (HCG). The positive response to FSH is attributed by us to the contamination of the preparation with LH (2 to 3% by manufacturer''s assay). It is suggested that this rapid and sensitive response to LH might be utilized to assay the purity of FSH preparations.