Expression of neuropeptide substance P during wound healing of deep partial thickness scalding in diabetic rats / 上海第二医科大学学报

ABSTRACT

Objective To study the expression and change of neuropeptide substance P (SP) during the wound healing of deep partial thickness scalding in diabetic rats. Methods Eighty-four Wistar rats were randomly divided into diabetes mellitus group (n=42) and control group (n=42). Diabetic rat models were established by intraperitoneal injection of streptozotocin (STZ) in diabetes mellitus group, and those in control group were intraperitoneally injected with aseptic citrate buffer solution. Deep partial thickness scalding with diameter of 2 cm on the back were prepared in all the rats. The pre-scalding and post-scalding wound specimens of different time points were obtained, and the percentages of wound closure were calculated. The wound specimens were also obtained for immunohistological staining to compare the areas with positive staining of SP, and ELISA was employed to detect the expression of SP in the wound tissues. Results The percentage of wound closure was significantly lower in diabetes mellitus group than that in control group from 7 days post-scalding (P< 0.01). The areas with positive staining of SP in diabetes mellitus group were much smaller than those in control group at different time points, which was most significant on the seventh day post-scalding[(1 350.93±99.28) μm2 vs(1 715.86± 103.41) μm2](P < 0.01). The expression of SP in the wound tissues was significantly lower in diabetes mellitus group than that in control group at different time points, which was most significant on the seventh day post-scalding[(114.04±9.96) vs(143.39±8.94)](P<0.01). Conclusion The significantly lower expression of SP in wound site may be one of the causes of delayed wound healing in diabetic rats.