Experimental study of insulin receptor change from bladder after conus medullaris injury in rats

Abstract

Objective To observe the change rules of insulin receptor from rat bladders after losing lower cental innervations so as to explore the function of insulin receptor in denervated bladder. Methods From January, 2016 to June, 2017, 40 Sprague-Dawley rats were randomly divided into experimental group and control group,each group was 20. The conus medullaris of rats in experimental group were damaged, and rats in control group received sham operation. The rats in 2 groups were sacrificed at different time after surgery (1 day, 1 week, 1 month, 3 months). Bladder specimens were harvested to perform wet weight measurement and immunohistochemical detection of insulin receptor. Results Corresponding to 1 day, 1 week, 1 month and 3 months after surgery, the bladder wet weight of control group were (0.089±0.022) g, (0.094±0.038) g, (0.106±0.112) g and (0.102±0.048) g, and of experimental group were (0.092±0.026) g, (0.110±0.034) g, (0.538±0.098) g and (1.528±0.462) g. One month and 3 months after surgery, bladder wet weight of ex-periment group were significantly increased as compared with those of control group (P<0.05). One day, 1 week, 1 month and 3 months after the operation, the positive rate of insulin receptor expression was 60%, 100%, 100% and 80%. And strongly positive rate was 55%. In control group, the positive rate of insulin receptor expression was 20%, 40%, 40%, and 0%. The expression of insulin receptor in experimental group was significantly higher than that in control group in every stage (P<0.05). Conclusion The expression of insulin receptor is significantly increased after denervation of bladder. The defections of insulin receptor might lead to apoptosis and muscle wasting after denervation. Restore insulin receptor function might be key point to prevent bladder tissue from irreversible damage. Key words: Conus medullaris; Insulin receptor; Bladder; Denervation