兔耳增生性瘢痕的形态学观察与羟脯氨酸含量变化

Morphological observation and changes of hydroxyproline content in hypertrophic scar of rabbits

目的 建立动物增生性瘢痕实验模型 ,并探讨其胶原代谢特点与形态学变化规律。方法 用圆形钻刀在兔耳腹面产生直径 6mm的全层皮肤缺损创面 6 4个 ,分别在术后 1 4、2 1、35、70和 98d进行形态学观察与羟脯氨酸含量测定。结果 术后 2 1d ,76 %的创面 ( 4 5 /5 9)有突出瘢痕形成 ,术后 35d ,瘢痕增生达高峰 ,厚度平均为 2 .0 5mm ,术后 70d ,瘢痕变薄 ,术后 98d ,46 %的突出瘢痕 ( 1 1 /2 4)消失 ;组织学观察示术后 2 1、35d有大量增殖成纤维细胞和旋涡状排列胶原纤维 ,术后 70、98d突出瘢痕内成纤维细胞减少 ,但不规则排列纤维仍存在 ;术后 2 1d ,瘢痕组织内羟脯氨酸含量增加 ,显著高于正常兔耳皮肤 (P <0 .0 5 ) ,35d时羟脯氨酸含量约为正常皮肤的 3倍 ,术后 98d的羟脯氨酸含量亦显著高于正常皮肤 (P <0 .0 5 )。结论 胶原大量沉积是动物增生性瘢痕的胶原代谢特征 ;动物正常愈合瘢痕转化为增生性瘢痕发生在术后 1 4～ 2 1d ;动物增生性瘢痕形成快 。

Objective To establish animal model for hypertrophic scar and study the characters of its morphology and collagen metabolism. Methods A total of 64 round wounds (diameter of 6 mm each) with total skin loss were made on the ventral side of rabbit ear using a trephine. Morphology and collagen metabolism of scar wounds were studied at 14,21,35,70 and 98 days after operation, respectively. Results There were 76% elevated scars developed (45/59 wounds) on the ventral side of rabbit ear at 21 days and 46% elevated scars disappeared (11/24) at 98 days after operation. There were numerous fibroblast proliferation and whorl arranged collagen fibers at 21 and 35 days. The number of fibroblast decreased, but irregular arranged fibers still presented in the elevated scars at 70 and 98 days after operation. Hydroxyproline content in elevated scars at 21 days was higher than that in normal skin ( P <0.05), and at 35 days was 3 times as that in normal skin and at 98 days was also markedly higher than that in normal skin ( P <0.05). Conclusion Excessive deposition of collagen is a characteristic of hypertrophic scar in rabbits. The conversion of normal scarring to hypertrophic scarring in rabbits occurs at 14～21 days after operation. Both development and regression of hypertrophic scar in rabbit are quicker than that in human.