Plasma Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH) Suppression in the Cryptorchid Ram by a Non‐Steroid Factor (Inhibin) from Ram Rete Testis Fluid

Abstract

Cryptorchid rams were bled every 15 or 30 min for 25 h. 20 ml of charcoal treated RTF were injected at the 5th and at the 6th h after the beginning of sampling. Human serum albumin or γ‐globulin were injected similarly as controls. FSH, LH, testosterone and prolactin were measured by radioimmunoassay. A non‐steroid factor from RTF suppresses the secretion of both FSH and LH but with different kinetics. FSH is progressively lowered after the first injection and a plateau (30% of depletion) is observed about 8 h after the first injection and lasts for about 7 h. RTF injections result in the suppression of LH peaks for 3 to 5 h starting at the first two h after treatment.