Hypothalamus pituitary testis interaction

Abstract

The recent observation by Schally & co authors that the release of both LH and FSH is dependent upon the one 'releasing' hormone (LH RH) has made the study of the hypothalamus pituitary testis axis much more complex. Furthermore, the normal maintenance of both spermatogenesis and testosterone secretion depends upon LH and FSH acting synergistically. It may, therefore, be surmised that there is no absolute specificity of gonadal steroids or other substances in the regulation of secretion of gonadotrophins. Nevertheless, FSH and LH secretion appear to be dissociated in certain pathological conditions. When the Leydig cells are normal but the germinal epithelium has been damaged or destroyed, as after irradiation, certain viral infections, the administration of anti fertility agents or in idiopathic infertility, the LH levels stay within the normal range whilst those for FSH are elevated. This paper examines the basal secretion of the gonadotrophins (mainly LH and to a lesser extent FSH) and the response in males to administration of steroids and LH RH, and also the relationship between spermatogenesis and gonadotrophins.