Diabetes, insulin-mediated glucose metabolism and Sertoli/blood-testis barrier function.

Blood testis barrier (BTB) is one of the tightest blood-barriers controlling the entry of substances into the intratubular fluid. Diabetes Mellitus (DM) is an epidemic metabolic disease concurrent with falling fertility rates, which provokes severe detrimental BTB alterations. It induces testicular alterations, disrupting the metabolic cooperation between the cellular constituents of BTB, with dramatic consequences on sperm quality and fertility. As Sertoli cells are involved in the regulation of spermatogenesis, providing nutritional support for germ cells, any metabolic alteration in these cells derived from DM may be responsible for spermatogenesis disruption, playing a crucial role in fertility/subfertility associated with this pathology. These cells have a glucose sensing machinery that reacts to hormonal fluctuations and several mechanisms to counteract hyper/hypoglycemic events. The role of DM on Sertoli/BTB glucose metabolism dynamics and the metabolic molecular mechanisms through which DM and insulin deregulation alter its functioning, affecting male reproductive potential will be discussed.