Study On The Morphologic Changes Of Interstitial Cells Of Cajal-like Cells In Diabetic Guinea Pig Bladder

Objective: To establish a guinea pig model of diabetic cystopathy and do some research on changes of quantity and ultrastructure of ICC-like cells in urinary bladder.Methods: The guinea pigs of diabetes group were induced by a single intraperitoneal injection of streptozotocin(STZ). Six weeks later,both goups were weighed, then fasting blood glucose and glucose tolerance were detected. Guinea pigs, that conformed to the diabetic standard, were raised 4 weeks more. The urodynamic evaluation was accepted by both groups. The distribution and ultrastructure changes of ICC-like cells, were observed by immunofluorescence methods and under electronmicroscope.Results: Six weeks after STZ injection, the average weight of diabetic group (311.16±43.47) g was significantly lower than that of control (401.00±27.17) g (P <0.01); the average fasting plasma glucose of diabetic group (6.88±1.172)mmol / L was significantly higher than that of control group (4.91±0.61)mmol / L (P <0.01); the average glucose tolerance of diabetic group (14.11±4.85 mmol / L) was significantly higher than that of control group(6.88±1.172) mmol / L (P <0.01). The achievement ratio of STZ induction was 44.12% (15/34), the mortality rate was 5.6% (2/36).Ten weeks after STZ injection,in the diabetic group, the average maximum detrusor pressure (19.20±2.93)cmH2O was signifently lower than controls (25.09±2.12)cmH2O (P<0.01); the average threshold pressure for leakage (3.00±1.13) cmH2O was signifently higher than controls (1.91±0.70) cmH2O (P<0.05); maximum bladder capacity (1.94±0.24) ml was significently higer than controls (1.65±0.46) ml (P<0.05); the average residual urine (0.41±0.31) ml was significently higer than congtrols (0.00±0.00) ml (P<0.01); the average bladder compliance (0.564±0.197)ml/cmH2O was significently lower than controls (0.925±0.441) ml/cmH2O (P<0.01). ICCs-like cells were identified to exist in the detrusor of guiea pig bladder. In the bladder, KIT positive cells were seen at the edge of smooth muscle bundles and within the bundles,all in parallel with the muscles.These cells were spindle-shaped ,which characterized by bipolar cells. In detrusor,compared with control, the ICC-like cells of diabetes group showed significently decreased in quantity. In diabetic bladder, the quantity of gap junctions between ICC-like cells and cells around,such as smoth muscle cells,terminal nerves and other ICC-like cells,decreased significently.And more cavities and less organoids occurred in cytoplasm of diabetic ICC-like cells. Mitochondria became swollen or even disapeared, accompanied with swollen endocytoplasmic reticulum.Conclusion: The decrease in quantity and injures in ultrastructure of ICC-like cells may play a role in DCP of guinea pig.