Physiology and endocrinology of spermatogenesis

Abstract

Spermatogenesis is the process by which the primordial germ cells transform into highly specialized mature spermatozoa. This is a complex process which takes place in the seminiferous tubules of the male gonad (Testis). Spermatogenesis results in the generation of daughter cells which can transfer the genetic material to the next generation through the process of reproduction. The entire spermatogenic process can be broadly classified into four important steps. This process is under the control of several extrinsic and intrinsic factors. Hypothalamo Pituitary Testicular axis which involves gonadotropin releasing hormone (GnRH) neurons with its upstream regulators, gonadotropins (Follicle Stimulating Hormone and Lutenizing Hormone) and the testosterone form the major regulators of spermatogenesis. Sertoli cells (SC) are the major intrinsic factor controlling spermatogenesis. Apart from providing structural and immunological support to the germ cells, SC also secrete Inhibin B which acts in paracrine mechanism supporting spermatogenesis. A thorough knowledge of the interplay of the endocrine factors in spermatogenesis is the basis for the effective management of male infertility.