Abstract: Objective To investigate the expression of connexin43 (Cx43) in diabetic cystopathy (DCP) and study its significance. Methods Fifty guinea pigs were randomly divided into DCP group (n=30), sodium citrate group (n=10) and blank control group (n=10). Diabetic model was established by intraperitoneal injection of streptozotocin in DCP group. Diabetic bladder guinea pigs were screened by urodynamics test. The sodium group was intraperitoneally injected with sodium citrate solution, and the blank control group was injected intraperitoneally with normal saline. The location and distribution of Cx43 in the three groups of bladder detrusor were observed by immunohistochemical staining, and expressions of Cx43 proteins were detected by Western blot assay. Results Immunohistochemical staining showed that the intensity of Cx43-specific staining was significantly lower in DCP group than that in the other two groups. There was no significant difference in the positive staining intensity between sodium citrate group and blank control group. Western blot analysis showed that the expression of Cx43 protein was significantly lower in bladder tissue of DCP group (0.52±0.02) than that of blank control group (0.68±0.02) and sodium citrate group (0.70±0.03, P＜0.01). There was no significant difference in the expression of Cx43 protein in the bladder tissue between the sodium citrate group and blank control group (P＞0.01). Conclusion The decreased expression of Cx43 in detrusor tissue plays an important role in the formation of diabetic bladder and may be a new starting point for studying the pathogenesis of diabetic bladder.

Key words: connexin43, gap junction, gap junction intercelluar communication, diabetic cystopathy, streptozotocin