Changes Of The Function Of Renal Pelvis Smooth Muscle And Ultra Microstructure Of Mitochondria In Partialunilateral Ureteral Obstruction Rats

Objective：To observe the changes of the function of renal pelvis smooth muscle andultra microstructure of mitochondria in partial unilateral ureter obstruction.Methods：Eighty male Wistar rats were randomly divided into two groups: shamcontrol group (only received laparotomy)and experiment group (with the upper half of ureterembedded into the psoas muscles). At different time points (8-week and 16-week)，the renalpelvises were caught out, then the contraction frequency and extent of the muscle strips weredetermined. And the changes of ultra microstructure of mitochondria in the renal pelvis smoothmuscle cell were observed by transmission electron microscope.Result：The contraction frequency and contractile force of smooth muscle in renalpelvis were 9.68±3.24 times / 30 seconds and 0.45±0.13g in 8-week experimental group, and8.47±2.19 times / 30 seconds and 0.24±0.10g in the 8-week sham control group.They were7.32±1.56 times / 30 seconds and 0.13±0.05g in 16-week experimental group,and 8.29±2.26 times / 30 seconds and 0.22±0.09g in the 16-week sham control group.Compare with thesham control group, the contraction frequency and contractile force of smooth muscle fromrenal pelvis in experimental group were increased at 8-week time point(P<0.05), and decreasedat 16-week time point(P<0.05). They were no statistic changes between 8-week and 16-weeksham control groups(P>0.05), while they were significantly higher in 8-week than 16-weekexperiment group(P<0.05). Mitochondria in the renal pelvis smooth muscle cells at 8-weektime point were significantly increased,but microstructure were hardly normal. Mitochondria inthe renal pelvis smooth muscle cells at 16-week time point were decreased, the ridgedisappeared, swelling and empty bubbled,and a large number of collagen fibers appearanced inintercellular substance.Conclusion：Partial unilateral ureter obstruction can enhance the contraction fuction ofsmooth muscle from renal pelvis at 8-week time point. However, the contraction fuction ofsmooth muscle in renal pelvis are decreased at 16-week time point.