局部应用胰岛素对大鼠烫伤创面基底膜形成的影响

目的观察胰岛素对大鼠深Ⅱ度烫伤再上皮化创面基底膜(BM)形成的影响。方法将96只SD大鼠背部造成45cm2深Ⅱ度烫伤,根据创面皮下注射药物的不同分为对照组(创面皮下浸润注射2ml等渗盐水,48只)和胰岛素组(创面皮下浸润注射0.1U长效混悬锌胰岛素 等渗盐水2ml,48只)。两组大鼠均在伤后第1天开始注射,1次/2d,直至创面完全上皮化。于伤后2、3、4、5、6、10、14d及创面完全再上皮化时,每组每时相点处死6只大鼠,取创缘1cm宽皮肤,利用网状纤维染色及透射电镜观察创面BM形态,用蛋白印迹法测定角质形成细胞(KC)层粘连蛋白(LN)5mRNA表达水平和LN含量。结果胰岛素大鼠组再上皮化创面BM结构清晰完整。伤后10、14d胰岛素组LN-5mRNA表达水平高于对照组(P<0.05或0.01)。创面完全再上皮化时两组大鼠LN-5mRNA表达水平均减弱。伤后14d及创面完全再上皮化时胰岛素组LN的蛋白表达量各为56±8、101±13,显著高于对照组39±5、73±16(P<0·05).结论烫伤创面皮下浸润注射0.1U胰岛素可以加速创面再上皮化,改善再上皮化创面质量。

The influence of topical application of insulin on the formation of basement membrane in scalded rats

OBJECTIVE: To investigate the influence of topical application of insulin on the formation of basement membrane (BM) in rats with deep partial thickness scald. METHODS: Ninety-six SD rats were inflicted with deep partial thickness scald on the back and were randomized into A group (n = 48, with subcutaneous injection of 2 ml of isotonic saline on the 1 post scald day (PSD)) and B group (n = 48, with subcutaneous injection of 0.1 U of insulin and 2 ml of isotonic saline on the 1 PSD). The rats received the treatment every other day until wound re-epithelization completed. Then the rats were sacrificed on 2, 3, 4, 5, 6, 10, 14 PSD, and on the day when the wound re-epithelialized completely. The skin samples of 1 cm in width were harvested at the edge of the wound for reticular fiber staining and for morphological observation of the wound BM with transmission electron microscope. The expression of laminin-5 mRNA and laminin in keratinocyte was determined by RT-PCR and Western blotting, respectively. RESULTS: Integrated and continuous structure of the basement membrane was observed in B group. Laminin-5 mRNA expression was much higher in B group than that in A group on 10 and 14 PSD (P < 0.05 or P < 0.01). Laminin-5 mRNA expression was decreased in both groups when epithelialization completed. But the Laminin-5 protein expression on 14 PSD and the day of epithelization (56 +/- 8, 101 +/- 13) was obviously higher in B group than that in A group (39 +/- 5, 73 +/- 16), (P < 0.05). CONCLUSION: Subcutaneous injection of 0.1 U insulin beneath the scald wound is beneficial to the acceleration of the wound re-epithelialization process, and to the improvement of the wound healing quality.