Increased secretion of müllerian inhibiting substance after immunological blockade of endogenous luteinizing hormone releasing hormone in the rat

Abstract

In order to evaluate the role of leuteinizing hormone releasing hormone (LHRH) and gonadotropins in the control of secretion of Müllerian inhibiting substance, groups of pregnant rats were injected intraperitoneally with high potency antiserum from a rabbit immunized with LHRH. Pregnant females were injected at 13 and 20 days of gestation with LHRH antiserum or an equal volume of normal rabbit serum as a control. The testes and penis were reduced in weight and size in 6-day-old pups of the experimental group indicating the luteinizing hormone (LH) was blocked and that LHRH antiserum was active. Testicular fragments of 17-day fetuses and 6-day-old pups showed an increase relative to controls in Mullerian inhibiting substance activity in a graded organ culture bioassay system. These studies suggest that secretion of Mullerian inhibiting substance is curtailed by one or both gonadotropins. Speculation: The secretion of Mullerian inhibiting substance is under inhibitory gonadotropin control, dependent on normal hypothalamic secretion of LHRH. © 1978 International Pediatric Research Foundation, Inc.