Ultrasound Imaging And Ultrastructural Changes Of Bladder In Diabetic Rats

Objective:To investigate the ultrasound imaging and ultrastructure changes of bladder in diabetic rats.Materials and Methods:From November 2019 to October 2020,54 healthy male Sprague-Dawley rats weighed 200g were randomly divided into control group(n=18),white granulated sugar feeding group(n=18)and streptozotocin-induced diabetes mellitus group(n=18).Osmotic diuresis was imitated by drinking sugar-sweetened water daily.Cystometry were performed for rats after 6 weeks.The 24-hour drinking and urine volumes were calculated at 6 and 21 to 31 weeks respectively.Using ultrasound to measure the bladder morphology after fasting water for 3 to 5 hours after 46 weeks.The rats were sacrificed and 1 mm~3dome of bladder tissue was quickly dissected for the transmission electron microscope after 47 weeks.The mitochondrial vacuolar degeneration in the detrusor were quantified.Results:(1).No significant difference of the intravesical pressure was found among three groups.(2).The drinking and urine volumes in the sugar group were significantly higher than the control group(drinking:P<0.001,urine:P<0.001).The drinking and urine volumes in the diabetic group were significantly higher than the control group(drinking:P<0.001,urine:P<0.001).The drinking and urine volumes in the diabetic group were significantly higher than the sugar group(drinking:P<0.001,urine:P<0.001).(3).The BWT in the sugar group was thicker than the control group(P=0.043).The BWT in the diabetic group was thicker than the control group(P<0.001).No significant difference of the BWT was found between sugar and diabetic groups(P=0.085).The length of bladder in the sugar group was longer than the control group(P=0.005).The length of bladder in the diabetic group was longer than the control group(P=0.033).The depth of bladder in the sugar group was longer than the control group(P=0.012).The depth of bladder in the diabetic group was longer than the control group(P=0.006).Two rats in the sugar group revealed obvious urinary retention(2/9).Two rats in the diabetic group showed obvious urinary retention(2/8).Two rats in the diabetic group showed multiple bladder stones(2/8).(4).The mucosal denudation and necrosis were observed in the sugar and diabetic groups.The mitochondrial vacuolar degeneration in the umbrella cells and urothelial cells were observed in the diabetic group.The submucosa vascular endothelial cells hyperplasia with a narrowed lumen were observed in the diabetic group.The mitochondrial vacuolar degeneration in the detrusor were more severe in the sugar group than in the control group(P<0.001).The mitochondrial vacuolar degeneration in the detrusor were more severe in the diabetic group than in the control group.The axon degeneration was observed in the diabetic group.Two rats with hyperglycemia in the sugar group share similarities with diabetes group.Conclusions:Long-term diabetes mellitus can cause the increment of urinary bladder morphology and bladder wall thickness,urinary retention and bladder stones.The histological degeneration of the vesical mucosa,vasculature,detrusor muscle and axon might be the pathological bases of DCP.