Effect of melatonin on testicular damage in streptozotocin-induced diabetes rats.
BACKGROUND
It is well known that diabetes mellitus is associated with impairment of testicular function. In the present study, we aimed to demonstrate the effect of melatonin on testicular damage in male rats with streptozotocin (STZ)-induced diabetes.


METHODS
Male Wistar rats were divided into 4 groups: (1) control group, (2) melatonin-treated nondiabetic group, (3) diabetic group and (4) melatonin-treated diabetic group. Diabetes was induced by STZ injection. Melatonin was administered intraperitoneally at the dose of 10 mg/kg for 5 days. Testicular damage was examined by using hematoxylin and eosin staining and periodic acid-Schiff staining, and apoptosis was determined by terminal-deoxynucleotidyl-transferase-mediated dUTP nick end labeling (TUNEL). Potential disorders associated with seminiferous tubular sperm formation were evaluated using the Johnsen score.


RESULTS
Diabetic rats showed a reduction in seminiferous tubule diameter, increased thickening of the basement membrane in seminiferous tubules and degenerated germ cells. TUNEL-positive cells were significantly more numerous in diabetic rats than in control rats. Melatonin significantly attenuated the diabetes-induced morphological changes and germ cell apoptosis in the diabetic rat testis. The number of polymorphonuclear leukocytes was significantly decreased in group 4 when compared to group 3.


CONCLUSIONS
These results suggest that intraperitoneal administration of melatonin for 5 days is a potentially beneficial agent to reduce testicular damage in adult diabetic rats, probably by decreasing oxidative stress.
Guneli
E
E
Department of Laboratory Animal Science, Institute of Health Science, Izmir, Turkey.
Tugyan
K
K
Ozturk
H
H
Gumustekin
M
M
Cilaker
S
S
Uysal
N
N
D000818:Animals; D000975:Antioxidants / Q000627:therapeutic use*; D003921:Diabetes Mellitus, Experimental / Q000150:complications*; D004801:Eosine Yellowish-(YS); D005456:Fluorescent Dyes; D006416:Hematoxylin; D020287:In Situ Nick-End Labeling; D008297:Male; D008550:Melatonin / Q000627:therapeutic use*; D010503:Periodic Acid-Schiff Reaction; D051381:Rats; D017208:Rats, Wistar; D012671:Seminiferous Tubules / Q000473:pathology*; D013733:Testicular Diseases / Q000188:drug therapy* / Q000209:etiology / Q000473:pathology
D000975:Antioxidants; D005456:Fluorescent Dyes; D008550:Melatonin; D004801:Eosine Yellowish-(YS); D006416:Hematoxylin