ABSTRACT
Diabetes mellitus is a global disabling and deadly disease found world-wide. Altered testicular structure and function have been observed in diabetic human and animal models of diabetes with impaired reproductive function. The testicular atrophy and infertility were common in untreated or poorly controlled diabetics. The present study was carried out to compare the protective effect of melatonin and chromium against testicular alterations in alloxan-induced diabetes in albino rats. Thirty-five adult male albino rats were used in this study. The animals were divided into two main groups [each five]: non diabetic and diabetic rats, the first group was subdivided into 3 sub-groups: normal control, melatonin-treated animals and chromium-treated animals. The second group was subdivided into 3 sub-group [each five]: diabetic, diabetic rats treated with chromium, and diabetic rats treated with melatonin. Diabetes was induced by a single intra-peritoneal injection of alloxan monohydrate in dose of 60 mg/ kg body weight [BW]. The experiment was carried for forty-two days. Computer image analysis was used to measure the thickness of the basement membranes of the seminiferous tubules, the perimeter of the seminiferous tubules and the number of Leydig cells. In diabetic rats the seminiferous tubules showed statistically significant decrease in diameter, irregular outline and deformed shape because there was degeneration and disappearance of germ cells from many tubules. There was significant thickening of the basement membrane of the seminiferous tubules also detected. Ultrastructurally, nuclei of germ cells showed rarefied chromium and separated areas of nuclear envelop. Spermatids showed abnormal condensed nuclear chromatin surrounded by membranes with focal areas of discontinuity together with vacuolation of Sertoli cell cytoplasm. Melatonin and chromium improved the diabetic alteration in the basement membranes, diameter of the seminiferous tubules and the number of Leydig cells but they did not return to the control values. The improvement with melatonin was more than that with chromium. From the present study, it could be concluded that, melatonin and chromium showed a protective effect on histological alterations of the testis of alloxan-induced diabetes in rats