P物质和降钙素基因相关肽在胎兔皮肤无瘢痕愈合中的作用

Changes in neuropeptide substance P and calcitonin generelated peptide in scarless wound healing in fetal rabbit skin

目的 探讨神经肽 P物质 (SP)和降钙素基因相关肽 (CGRP)在无瘢痕愈合中的作用。方法 建立胎兔背部皮肤全层切割伤模型 ,采用免疫组化方法观察神经肽 SP和 CGRP在胎兔创伤愈合中的动态变化特点 ,并与正常胎兔、创伤成兔和正常成兔进行比较。结果 胎兔皮肤愈合快 ,伤后 3～ 5 d完全无瘢痕愈合 ;成兔伤后第 7d瘢痕愈合。胎兔皮肤伤后 SP和 CGRP阳性表达降低 ,以第 2 d最明显 ,分别为正常胎兔的 75 %和 80 % (P均 <0 .0 1) ,然后逐渐恢复正常 ;成兔皮肤伤后第 1d SP和 CGRP表达明显降低 ,分别为正常成兔的6 0 %和 76 % (P均 <0 .0 1) ,以后明显增加 ,第 7d达高峰 ,为正常成兔的 16 8%和 12 6 % (P均 <0 .0 1) ,然后下降 ,第 14 d与正常成兔基本相似。结论 神经肽 SP和 CGRP的低表达在胎兔皮肤无瘢痕愈合中可能起重要作用。

Objective To explore the role of the neuropeptide in fetal scarless wound healing. Methods The animal models were replicated in which a fullthickness wound was inflicted on the back of rabbit fetuses at 22 days gestation(term=31 days). The progress of wound healing was observed on microand macrolevels at the 1 st, 2 nd, 3 rd, 5 th, 7 th, 14 th postinjury days respectively. The expression level of substance P(SP) and calcitonin generelated peptide (CGRP) during wound healing was assessed by immunohistochemistry staining. Results The cutaneous wounds in fetal rabbits healed more rapidly than that in adult and without the formation of scar. The expression of SP and CGRP of wound decreased in fetal rabbit at the early stage postinjury, down to the lowest levels on the 2 nd postinjury day(75%, 80%, vs. fetal control, both P <0 01), then increased gradually,up to the normal levels. The expression of SP and CGRP of wound decreased in adult rabbit at the early stage postinjury, down to the lowest levels on the postinjury 1 st day(60%, 76%, vs. adult control , both P <0 01), then increased quickly, up to a higher level than normal group, reaching the peak on the postinjury 7 th day(168%, 126%, vs. adult control , both P <0 01), then returned to the normal levels. Conclusion The low level of neuropeptide may contribute to scarless wound healing in fetal rabbit.