Role of prolactin on epididymal glycoprotein metabolism in matured monkeys, Macaca radiata: specific activities of glycosyltransferases and glycosidases.

Impact of altered serum prolactin status on enzymes involved in glycoprotein metabolism in epididymal tissue of matured monkeys was studied. Hyperprolactinemia (ovine prolactin-250 micrograms/kg body weight/day for 30 days) significantly inhibited the specific activities of dolichylphosphate mannosyl transferase, dolichylphosphate glucosyl transferase and galactosyl transferase, in the epididymal tissues. However, it had an enhanced effect on epididymal glycosidases such as beta-galactosidase, beta-N-acetyl glucosaminidase, beta-N-acetyl galactosaminidase, alpha-mannosidase and alpha-L-fucosidase. Hypoprolactinemia (bromocriptine mesylate-1-mg/kg body weight/day for 30 days) on other hand had no significant effect on the specific activities of both, glycosyltransferases and glycosidases, in the epididymal tissues. The results suggest that hyperprolactinemia inhibits epididymal glycoprotein metabolism by impairing the incorporation of oligosaccharide units into proteins with enhanced degradation. This may have adverse effect on events leading to sperm maturation in epididymal environment.

Impact of hyperprolactinaemia on testicular neutral lipids and phospholipids in mature bonnet monkeys, Macaca radiata (Geoffroy).

Impact of hyperprolactinaemia, induced by daily injection of ovine prolactin (250 micrograms/kg body weight, ip for 30 days) on testicular lipids was studied in M. radiata. Wet weights of testis and accessory sex organs decreased in hyperprolactinaemic monkeys. Even though total lipids in the testis did not show any significant change, total cholesterol and total glyceride glycerol decreased. While all fractions of testicular neutral lipids showed a perceptible decrease, phosphatidic acid, phosphatidyl ethanolamine and phosphatidyl choline increased in hyperprolactinaemic monkeys. Hyperprolactinaemia appears to influence male fertility by altering the composition of testicular neutral lipids and phospholipids.