Diabetes is one of the leading causes of death in the developed societies. Diabetes type-2 accounts for almost 90% of the diabetes cases worldwide. Among the complications which are induced by diabetes is bladder dysfunction. In the current study we created a short-period diabetes type-2 model in order to investigate oxidative stress-related alterations in the bladder. Additionally treatment with the antioxidants resveratrol or taurine was provided in order to examine the effects of antioxidant treatment in the diabetes-induced alterations in the initiation of the disease.
Diabetes was induced in 8-week-old male Wistar rats with a single dose of streptozotocin (40mg/kg) intraperitoneally (i.p.). The next day the animals were randomly separated into 3 groups and for 14 days they followed a high fat diet. One group received no treatment (DM group), another group received orally resveratrol (10mg/Kg; Resv group) and the third one received taurine i.p. (1g/Kg; Tau group). Age matched control animals were used and were fed with normal diet (Control group). Two weeks later animals were sacrificed and bladders were processed for histological evaluation, measurements of malondialdehyde (MDA) and immunohistochemistry (IHC) for oxidative stress markers.
After two weeks the animals in the three diabetic groups had significantly lower body weight compared to the control group. DM group demonstrated significantly higher ratio of bladder weight to body weight compared to the Control. The histological evaluation demonstrated that two weeks of diabetes induced a mild damage of the bladder tissue in the DM group such as abruption of the mucosa from the muscularis as well as edema in the transitional epithelium. Antioxidant treatment with resveratrol or taurine protected the bladder tissue and these alterations were not observed in the treatment groups. MDA levels in the bladder were significantly larger in the DM group compared with Control, Resv or Tau group. Fourteen days of diabetes without treatment in the DM group induced moderate to strong expression of oxidative stress markers: a) MDA, b) 4-Hydroxynonenal and c) DNA oxidative stress marker 8-deoxyguanosine as the immunohistochemistry results indicated compared with the other three groups.
The results of the present study indicate the importance of the prompt diagnosis of diabetes and how it can be crucial for the progression of the disease. Specifically in the bladder, it appears that both mild damage in structural level as well as oxidative damage in molecular level can be prevented by antioxidant treatment such as resveratrol or taurine.