Internal medicine and reproduction: male hypogonadism

Awareness of the complex relation linking reproductive function and other major organ systems has been increasing only recently. We have tried to delineate some recent advances in our knowledge of male reproductive function and its disorders as they relate to Internal Medicine. The regulation of Gn-RH secretion and the influence of Gn-RH on gonadotropin secretion are among the most interesting aspects of hypothalamic-pituitary function. The pulsatile pattern of LH secretion is of particular interest in relation to the influence of gonadotropin secretory pattern on testis response. In this regard oligozoospermia with elevated FSH levels and decreased frequency of LH pulses has been identified. Sertoli cells play an essential role in the control of spermatogenesis. We investigated some features of human Sertoli cell function in vitro. These cells secrete transferrin and ABP, and hABP has an affinity for DHT which is different from that of liver-produced SHBG. Seminal transferrin is closely linked to spermatogenesis in oligozoospermia as well as in azoospermia due to damaged spermatogenesis. As a third point of interest paracrine control of testis function, and especially the paracrine role of endogenous opiates and several growth factors are described. LH pulsatility was studied in several medical and endocrine disorders to investigate their impact on male reproductive function. An altered pattern of LH secretion was found in most of the diseases investigated, and in some instances there were hints of hypothalamic involvement. Finally the negative influence on male reproductive function of several drugs, commonly used in the practice of internal medicine is stressed.