The effect of exogenous oxytocin on streptozotocin (STZ)-induced diabetic adult rat testes

The aim of this study is to investigate the therapeutic and protective effects of oxytocin treatment on testicular tissue of diabetic rats, induced by streptozotocin (STZ), before and after onset of experimental diabetes. Wistar Albino rats were divided into four groups: 1) Control group (n:6): 0,3 ml saline solution was injected intraperitoneally (i.p.), 2) STZ group (n:6): single dose STZ (65 mg/kg) was injected ip for 4 weeks, 3) Pre Oxytocin group (n:6): 5 µg/kg of oxytocin was injected i.p. for 5 days interval before single dose of STZ injection for 4 weeks, 4) Post Oxytocin group (n:6): 5 µg/kg oxytocin was injected i.p. for 5 days interval following single dose of STZ injection for 4 weeks. Blood samples were obtained and measured by a glucometer at the beginning of experiment and once a week during the whole experiment. The diabetic rats whose blood glucose levels were more than 200 mg/dl were included to the experiment. Following sacrification at the end of the 4th week, testis tissue samples were taken to be processed for light and transmission electron microscopy. Blood samples were processed for malondialdehyde (MDA), glutathione (GSH) and Advanced Oxidation Protein Products (AOPP) measurements. Testicular paraffin sections were stained with Haematoxylin and Eosin (H&E) and Periodic acid-Schiff (PAS) reaction and evaluated by light microscopy. It was revealed that oxytocin treatment decreased the testicular damage which was more prominent in STZ group. Histopathological damage especially has been reduced in pre-oxytocin group compared to the post oxytocin group. According to biochemical data, MDA and AOPP levels were reduced, whereas GSH level was increased in oxytocin treated groups when compared to STZ group. As a result, we can conclude that oxytocin has a protective effects on STZ- induced diabetic rat testes. To conclude, we suggest that oxytocin might have an important role in protection of testicular tissue from diabetes.