ENDOCRINE BASIS FOR TESTICULAR FUNCTION IN THE STALLION

The specific nature and relative contribution of the various factors i nvolved in the endocrine/paracrine/autocrine control of reproductive f unction in normal stallions are not well defined nor have they been el ucidated in the idiopathic subfertile/infertile stallion. Over the las t 9 years, work in our laboratory has been focused in characterizing t he hypothalamic-pituitary-testicular axis in fertile, subfertile (idio pathic oligospermia) and infertile (idiopathic azoospermia) stallions. We have identified endocrine factors and mechanisms important for nor mal reproductive function, and demonstrated specific hormonal changes in pituitary and testicular function between fertile, subfertile and i nfertile stallions. Recent evidence suggests that the primary defect i s at the level of the testes. The nature of the dysfunction does not a ppear to involve changes in LK receptor binding kinetics but may be re lated to post-receptor mechanisms. (C) 1997 by Elsevier Science Inc.