Role Of Melatonin And Viyamin E In Resisting Oxidative Damage Of Diabetic Rat Bladder At Early Stage

Objective：To study the role of melatonin and vitamin E in protecting thebladder tissues of diabetic rat models from oxidative stress injury andcomplications caused by the imbalance between oxidants and antioxidants.Method:We created the diabetic models through lumbar injection ofstreptozotocin,and divided the rats into three goups,as diabetic controlgroup,vitamin E treatment group and melatonin treatmentgroup.Besides,another normal control group was brought in theexperiment.All the rats were lumbar injected by drugs or4%ethanolphysiological saline once a day.The dosages of vitamin E and melatoninwere respectively50mg/kg and2mg/kg.The diabetic control group andnormal control group were received4%ethanol physiological salinewith a dosage of2ml/kg.Four weeks later,we harvested the bladder tissuesafter anesthesia. The changes of ultrastructures of the samples wereobserved by electron microscope and the malonaldehyde (MDA), ReducedGlutathione (GSH) and Superoxide Dismutase (SOD) of the bladdersamples were measured. Result:The results of electron microscope of diabetic control groupshowed mitochondrias of smooth muscle cells,vessel endothelial cellsand mechanocytes were swelling and cavitating,and thrombus-likestructure was observed.The findings of vitamin E treatment group andmelatonin treatment group were much milder that that of the dabeticgroup.Compared with normal control group,the content of MDA ofdiabetic control group was distinctly elevated(p<0.01),while GSH(p<0.01) and SOD (p<0.01) were markedly lowered.After treatment withvitamin E and melatonin,MDA was obviously declined(p<0.01),GSH(p<0.01) and SOD (p<0.01) were strengthened.Compared melatonin withvitamin E,the effect on decreasing MDA and increasing GSH were muchbetter(p<0.01),while there was no significant diffrence on enhencing theactivity of SOD(p=0.512).Conclusion:Melatonin,which effect was much stronger than that ofvitamin E,could regulate the oxidative stress system in the bladder tissuesof diabetic rats,and protect the mitochondrias of smooth musle cells, vesselendothelial cells and mechanocytes from injured.