Fax +41 61 306 12 34 E-Mail karger@karger.ch www.karger.com Eur Surg Res 2008;40:354–360 DOI: 10.1159/000118032 Effect of Melatonin on Testicular Damage in Streptozotocin-Induced Diabetes Rats E. Guneli a K. Tugyan b H. Ozturk e M. Gumustekin c S. Cilaker b N. Uysal d a Department of Laboratory Animal Science, Institute of Health Science, and Departments of b Histology and Embryology, c Pharmacology and d Physiology, School of Medicine, Dokuz Eylul University, Izmir, and e Department of Pediatric Surgery, Medical School, Abant Izzet Baysal University, Bolu, Turkey cantly decreased in group 4 when compared to group 3. Conclusions: These results suggest that intraperitoneal ad- ministration of melatonin for 5 days is a potentially benefi- cial agent to reduce testicular damage in adult diabetic rats, probably by decreasing oxidative stress. Copyright © 2008 S. Karger AG, Basel Introduction Diabetes mellitus is a common health problem and a serious metabolic disorder associated with many func- tional and structural complications. Diabetes mellitus has adverse effects on male sexual and reproductive func- tions in diabetic patients and animals [1–4]. Both clinical and experimental studies revealed impairment of sper- matogenesis, reduced sperm count, sperm motility, sem- inal fluid volume and low testosterone levels in diabetic subjects [1–6]. Additionally, an experimental study indi- cated that diabetes mellitus produces reproductive dys- function but does not compromise the sperm-fertilizing ability in the cauda epididymis [7]. Apoptosis, known as programmed cell death, is a form of cell death that serves to eliminate dying cells in prolif- erating or differentiating cell populations. Apoptosis control is critical for normal spermatogenesis in the adult testes [6, 8] . The testis is sensitive to environmental expo- sure-induced cellular damage. Apoptosis of germ cells may occur during nonphysiological stresses such as dia- Key Words Diabetic testes injury  Melatonin  Germ cell apoptosis  Streptozotocin Abstract Background: It is well known that diabetes mellitus is associ- ated 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)-in- duced diabetes. Methods: Male Wistar rats were divided into 4 groups: (1) control group, (2) melatonin-treated non- diabetic group, (3) diabetic group and (4) melatonin-treated diabetic group. Diabetes was induced by STZ injection. Mel- atonin 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-deoxy- nucleotidyl-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 seminif- erous tubule diameter, increased thickening of the base- ment membrane in seminiferous tubules and degenerated germ cells. TUNEL-positive cells were significantly more nu- merous in diabetic rats than in control rats. Melatonin sig- nificantly attenuated the diabetes-induced morphological changes and germ cell apoptosis in the diabetic rat testis. The number of polymorphonuclear leukocytes was signifi- Received: July 12, 2007 Accepted after revision: December 4, 2007 Published online: February 26, 2008 Hayrettin Ozturk, MD Department of Pediatric Surgery, Medical School, Abant Izzet Baysal University TR–14280 Bolu (Turkey) Tel. +90 374 253 4656 3220, Fax +90 374 253 4615 E-Mail ozturkhayrettin@hotmail.com © 2008 S. Karger AG, Basel 0014–312X/08/0404–0354$24.50/0 Accessible online at: www.karger.com/esr Original Paper Downloaded by: Koç University 193.140.57.170 - 10/1/2013 4:12:03 PM