Hormonal Control of Male Reproductive Function

Hormones are key regulators of the reproductive system. These signaling molecules are transported in the blood stream to reach target organs in order to regulate physiologic processes and their function. The most relevant hormones for male reproductive system are those involved in the hypothalamus-pituitary-gonads axis. Through several stimuli, anterior pituitary produces luteinizing hormone and folliclestimulating hormone that act on testicular cells modulating both steroidogenesis and spermatogenesis. In fact, steroidogenesis, namely the production of testosterone, is crucial for the normal occurrence of spermatogenesis and for feedback actions to the pituitary and hypothalamus. However, spermatogenesis and Sertoli cells are also important to the regulation of this axis through the production of activin and inhibin B that, along with testosterone, also transmit feedback to the brain. Interestingly, in the last years, new intervenient have appeared in the regulation of male reproductive function with the discovery that adipose tissue is an endocrine organ and thus also produces hormones that may be important for this process. Along with the latter, gut hormones, which are related with the nutrient homeostasis, also modulate the function of testicular cells. In some cases, this interaction was only found due to metabolic disorders, like hyper- or hypothyroidism, obesity or diabetes mellitus. Herein, we propose to discuss the action and function of these hormones that interact with male reproductive system.

Keywords: Adipokines, Androgens, Estrogens, Follicle stimulating hormone, Ghrelin, Glucagon like peptide-1, Gonadotropin-releasing hormone, Hormonal control, Hormones, Luteinizing hormone, Obestatin, Resistin, Testosterone, Thyroid hormones, 5α-dihydrotestosterone.