糖尿病大鼠深Ⅱ度烫伤创面愈合过程中神经肽P物质的表达

目的 研究糖尿病大鼠深Ⅱ度烫伤创面中神经肽P物质(SP)表达及变化规律.方法 84只Wistar大鼠,随机分为糖尿病组和对照组,每组42只.糖尿病组腹腔内一次性注射链脲佐菌素(STZ)诱导建立糖尿病大鼠模型,对照组给予同等剂量的无菌柠檬酸缓冲液腹腔注射.所有大鼠麻醉后背部制成直径2 cm的深Ⅱ度烫伤创面.分别于烫伤前及烫伤后的不同时相采集创面组织标本,测算创面愈合率,免疫组化染色分析创面SP染色阳性区域面积,ELISA法创面组织中SP表达变化.结果 烫伤后第7天起,糖尿病组各时相点的创面愈合率均显著低于对照组(P<0.01).糖尿病组各时相点创面SP染色阳性区域面积均显著低于对照组,其中以烫伤后7 d时尤为显著,为(1 350.93±99.28)μm2 vs(1 715.86±103.41)μm2(P<0.01);糖尿病组各时相创面组织中SP表达均明显低于对照组,其中以烫伤后7 d时最为显著,为(114.04±9.96)vs(143.39±8.94)(P<0.01).结论 糖尿病大鼠创面组织中SP表达明显减少,可能是其创面难愈的原因之一.

Expression of neuropeptide substance P during wound healing of deep partial thickness scalding in diabetic rats

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.