GLUTS AND MAMMALIAN SPERM METABOLISM

Mammalian cells use glucides as a substrate that can be catabolized through glycolitic pathways or oxidative phosphorylation, used as a source of reducing potential, or to anabolic aims. An important role in supplying cells with energy is played by different membrane proteins that can actively (SGLT) or passively (GLUT) transport hexoses through the lipidic bilayer. In particular, GLUTs are a family of 13 proteins that facilitate the transport of sugars and that have a peculiar distribution in different tissues as well as a particular affinity for substrates. These proteins are also present in mature sperm cells, which, in fact, need carriers for uptake energetic sources that are important for maintaining cell basic activity as well as specific functions such as motility and fertilization ability. Likewise, several GLUTs have been studied in various mammalian species (man, bull, rat, mouse, boar, dog, stallion and donkey) to point out both their actual presence or absence and their localization on plasma membrane. The aim of this work is to give an overall picture of the studies available on GLUTs in mammalian spermatozoa at this moment, pointing out the species peculiarity, the possible role of these proteins and the potential future research on this item.