EFFECT OF GHRELIN ON TESTICULAR FUNCTIONS IN STREPTOZOTOCIN INDUCED TYPE 1 DIABETIC RATS

Abstract

Background: Oxidative stress is increased in diabetes mellitus (DM). Ghrelin is a peptide hormone produced by different tissues and its circulating level is decreased in type 1 DM. Recently, it has been shown to have antioxidant properties. Objective: This study was designed to investigate the effects of diabetes mellitus on pituitary testicular functions and the role of ghrelin in the modulation of these effects in a rat model of type 1 diabetes mellitus induced by streptozotocin. Materials and methods: 32 healthy adult male albino rats of initial body weight 170-195 gm were included. Rats were randomly and equally divided into 4 groups, group (1a): Vehicle treated (control) group, group (1b): Ghrelin treated normal group, group (IIa): STZ-diabetic group and group (IIb): Ghrelin treated diabetic group. Rats were weighed and examined for the serum levels of glucose, insulin, FSH, LH& testosterone levels, epididymal sperm count and motility, testicular malondialdhyde (MDA) level and superoxide dismutase (SOD), catalase (CAT) & glutathione peroxidase (GPX) activities and testicular weight(wt) & histopathology. Results: STZ-induced diabetes significantly decreased the body wt, testes wt, serum insulin, FSH, LH & testosterone levels, epididymal sperm count & motility and testicular SOD, CAT & GPX activities but significantly increased serum glucose & testicular malondialdhyde levels together with deterioration of the testicular histoarchitecture. Moreover, it was found that exogenous administration of ghrelin resulted in a significant recovery of all the above mentioned parameters in the diabetic group, while in the normal group, it was only associated with potentiation of the testicular antioxidant system as well as a significant increase in both the body and testes weights. Conclusion: Ghrelin has a potential protective role against diabetes-induced pituitary testicular dysfunction which may be due to its antioxidant properties and maintenance of glucose & insulin homeostasis.
Key words: Diabetes, Ghrelin, testicular function, oxidative stress.