Gamma GlutamylTranspeptidase Activity Determination in Epididymis of Corynorhinusmexicanus Bat Throughout Its Annual Cycle

Abstract

GGT initiates the degradation of both oxidized and reduced glutathione at the cell surface by cleaving the unique gamma glutamyl bond. The successive hydrolysis of oxidized or reduced CysGly by aminopeptidase or dipeptidase releases Gly, and cysteine/cysteine is recovered for intracellular synthesis of glutathione. In addition, GGT plays a major physiological role in providing cysteine to cells for GSH synthesis and protein synthesis, thereby playing a major role in antioxidant defense and normal growth. GGT is present in the epididymis, principally in caput. The catalytic activity of GGT is highest in the proximal epididymal regions and decreases toward the distal regions; participating in the epididymal sperm maturation process.In most mammals, epididymal sperm maturation takes place in a period not exceeding ten days, ending in the distal part of the corpus of the epididymis, before reaching the caudal region, which is responsible only for sperm storage; however, in C. mexicanus the epididymal sperm maturation ends in caudal epididymal region.For this reason, the main goal of the present study was to determine the relationship between the GGT activity through the caput and caudal epididymal regions, throughout annual cycle of Corynorhinus mexicanus bat.We found that the GGT activity appears to be important for epididymal sperm maturation in C. mexicanus bat in cephalic region, and important for protection against ROS epididymal caudal region.