胰岛素对表皮角质形成细胞的作用

目的 观察胰岛素对大鼠烫伤创面以及体外培养的表皮角质形成细胞（KCs）的作用，探讨其促进创面愈合的可能机制。方法水浴法致SD大鼠背部深Ⅱ度烫伤，局部创面下浸润注射生理盐水（对照组）或0．1U长效混悬锌胰岛素（胰岛素组），记录创面再上皮化时间；RT-PCR测定KCs表皮生长因子（EGF）mRNA表达；Western blotting检测KCs层粘蛋白（LN）表达。计算体外培养的人KCs经胰岛素作用后的细胞黏附率。结果 胰岛素组创面再上皮化时间较对照组明显缩短。胰岛素组大鼠KCs烫伤后第4、6d的EGFmRNA表达以及第14d和创面再上皮化当日的LN表达，均较对照组明显增强（P〈0．05）。体外培养的人KCs经胰岛素作用后，在不同细胞外基质上的黏附率均明显增加。结论胰岛素提高体外培养KCs的黏附能力并增强刨面局部KCs分泌EGF和LN的功能，是其促进创面愈合的可能机制。

Effects of Insulin on Keratinocytes

Objective To investigate the effects of insulin on the keratinocytes (KCs) in the rat wound and the KCs cultured in vitro. To explore the mechanism of topical insulin application on the acceleration of wound healing. Methods One hundred and nine SD rats were inflicted with deep partial thickness scalding on the back, and were randomized into control group and insulin group (treated with topical application of 0.1U of insulin). The time of re-epithelialization was recorded. The expression of epidermal growth factor (EGF) mRNA and laminin(LN) in the keratinocyte(KCs) was determined by RT-PCR and western blotting, respectively. The adhesion of KCs cultured in vitro after insulin administration was inspected. Results The re-epithelializing time of insulin group was significantly shortened than that of control group. The expression of EGF mRNA in insulin group increased significantly than that in control group at d4 and d6 post-burn day (P<0.05). The expressions of LN in insulin group were significantly greater than those in control group at d14 and at the and of re-epithelialization(P<0.05 ). The KCs adhesive rates to different extracellular matrix obviously increased after insulin administration. Conclusion Insulin can increase the adhesion of KCs cultured in vitro and is beneficial to promote the secretion of EGF and LN of KCs in the wound surface.This may be the mechanism of insulin on the acceleration of wound healing.