Evidence for the Existence in Spermatozoa of a Factor Inhibiting the Follicle Stimulating Hormone Releasing Hormone Synthesis

Abstract

A peptidic factor, isolated from bull spermatozoa and previously described as inhibiting ovarian maturation, reduces the release of follicle stimulating hormone (FSH) in the male rat, when administered intraventricularly. This action is still evident at a dose level of 100 ng. It seems reasonable to postulate that the factor acts at the level of central nervous structures, because the follicle stimulating hormone releasing hormone (FSH-RH) hypothalamic content is also greatly decreased. However, luteinizing hormone (LH) release and luteinizing hormone releasing hormone (LH-RH) are not affected by this factor.