[The male factor. I. Testicular function and gametogenesis].

The knowledge and treatment of human reproduction impairments have had an outstanding development during the last 15 years, mainly in topics related with infertility and sterility. Unfortunately in the area of male reproduction development has not been the same and despite the efforts accomplished, progress in the diagnosis and therapeutics of male infertility is limited. The functions of the male gonad are sperm production as well as the synthesis and secretion of steroid hormones, mainly testosterone. The efficient regulation of these functions depends on both the precise pituitary secretion of gonadotropic hormones and the endocrine, paracrine and autocrine responses of the testicular somatic cells to this stimulation. In this review we discuss the main events associated with the spermatogenic process, including the interactions among the testicular somatic cells and some characteristics of the physiological function of the hypothalamus-pituitary-testicle axis, as well as some pathophysiological states related to male infertility due to "pretesticular causes".