Testicular Signaling: Team Work in Sperm Production

The male gonads, testis, have two main functions: testosterone production (steroidogenesis), a fundamental hormone for the development and maintenance of several physiological functions; and sperm production (spermatogenesis), essential for male fertility. The synthesis of both products is mainly regulated by endocrine hormones, synthesized in the hypothalamus and pituitary gland, and paracrine signals. This chapter will explore the signaling pathways involved in testosterone production by Leydig cells. We will also discuss both classical and non-classical pathways of testosterone action in spermatogenesis, and the contribution of follicle stimulating hormone to spermatogenesis maintenance. Finally, the signaling pathways involved in blood-testis-barrier regulation as well as other paracrine signals involved in spermatogenesis control will be explored. Despite these pathways occur in most somatic cells, they have a unique role in regulating the most peculiar and exceptional process in one of the most complex tissue in male body.