Role of free radicle in bladder detrusor impairment to T2DM rats / 第三军医大学学报

ABSTRACT

Objective To explore the role and significance of free radicle in the pathophsiological mechanisms of diabetic cystopathy(DCP).Methods The detrusor strip contraction experiments were performed and observed in the group of type 2 diabetes mellitus(T2DM) rats at different time stages and the control group.The bladder tissue samples was made into homogenate,and the activities of superoxide dismutase(SOD) and the contents of malondialdehyde(MDA) were determined.Results The minimum stretch forces to induce the detrusor contractions in T2DM group were larger than the control group.Compared with the control group,the detrusor contractive frequency was higher in the period of 0 to 16 weeks,but was lower after the 20th week.The maximum detrusor contractive forces in the T2DM group showed a descended tendency with the elapse of the experiment time.In the bladder homogenate of the control group,the activities of SOD was declined after reaching the peak at the stage of 8th week,and then escalated at the stage of 24th week.As for the T2DM group,the activities of SOD became higher in the 4th week,than descended at the stage of 8th and 24th weeks.The contents of MDA in both groups showed descended tendency.In T2DM group,MDA became even lower than the control group in the 4th week and became higher than the control group in the 8th week.The ratio of SOD/ MDA in T2DM group was lower than the control group.In details,the ratio of SOD/MDA in T2DM group rose significantly in the 4th week,while declined in the 8th week.There was a negative correlation between the maximum detrusor contractive force and detrusor contractive frequency,and a positive correlation between the maximum detrusor contractive force and the contents of MDA.Conclusion The destrusor functions are impaired by Diabetes Mellitus.In the initial stage of DCP,the bladder functions are normal,because the detrusor had a high ability to remove the free radicle.In the progression stage of DCP,the bladder functions become decompensation,because the organism is seriously injured by the free radicle.So the impairment by free radicle is one of important mechanisms of destrusor impairment of diabetic cystopathy.