Reproduction and fertility

Abstract

The crucial participation of hormones in reproduction and fertility is the most complicated story in endocrinology, because it involves several organ systems; gametes as well as hormones; two classes of receptors and intracellular signals; and a myriad of environmental factors such as seasonal signals and, of course, the nearby presence of a conspecific carrier of the opposite gamete type. As complicated as this system is in mammals, being quite different among major classes, it is even more complex when one deals with the vast number of nonmammalian vertebrate species. In a marvelous recent review, Rothchild discussed the evolution of placental mammals from other vertebrates. This chapter is limited to two mammals: the rat, which has been the species of choice for elucidating basic science, and the primate, which is obviously of major interest in dealing with clinical issues. The rat runs a 4-or 5-day estrous cycle, from the onset of follicular growth under the influence of follicle-stimulating hormone (FSH), to ovulation following an luteinizing hormone (LH) surge. © 2005 Humana Press Inc.