咪喹莫特对兔耳增生性瘢痕动物模型的影响

目的探讨咪喹莫特对全层皮肤缺损诱导的兔耳增生性瘢痕模型组织学变化的影响及可能的作用机制。方法 24只新西兰白兔双耳腹面手术切除2.0cm×5.0cm全层皮肤至筋膜,建立兔耳增生性瘢痕模型后,随机分成两组,每组12只,将每只兔左耳分别于伤后每日和隔日应用咪喹莫特,共8周,右耳为空白组(非用药组)。结果与非用药组相比较,经咪喹莫特应用8周后,每日用药组的瘢痕厚度(431.22±92.03)、胶原含量(46.56±19.02)和瘢痕指数(0.36±0.31),TIMP-1(16.64±2.14),α-SMA(3.85±1.26)和PCNA(5.68±1.07)均有显著下降(P<0.05),MMP-1(6.71±2.03)显著增加(P<0.05);而隔日用药组,除胶原含量(49.48±17.35)和PCNA(5.33±0.67)有显著下降(P<0.05),MMP-1(5.05±0.76)显著增加(P<0.05)外,瘢痕厚度(621.91±96.81)和瘢痕指数(0.79±0.34),α-SMA(7.13±1.16)和TIMP-1(24.77±4.17)均无明显改变(P>0.05);无论每日还是隔日应用咪喹莫特对TGF-β1的表达均无影响(P>0.05)。结论在创伤早期应用咪喹莫特可降低瘢痕厚度和胶原含量。

Effects of Imiquimod on the Formation of Hypertrophic Scar in Rabbits

Objective To study the histological effects of imiquimod on the development of hypertrophic scar in rabbit ears induced by excision of full-thickness skin.Methods Hypertrophic scar model was established by excision of full-thickness skin(2cm×5cm)on the ventral surface of rabbits ears.A total of 24 New Zealand white rabbits were randomly divided into 2 equal groups with imiquimod on the left ears for 8 weeks.The right ears served as control without imiquimod.Results Compared with non-drug exposed,the dermal thickness(431.22±92.03),collagen content(46.56±19.02),scar index(0.36±0.31),TIMP-1(16.64±2.14),α-SMA(3.85±1.26)and PCNA(5.68±1.07)significantly decreased in scar with imiquimod daily(P<0.05);while the dermal thickness(621.91±96.81),scar index(0.79±0.34),α-SMA(7.13±1.16)and TIMP-1(24.77±4.17)were not significantly decreased in imiquimod every other day(P>0.05)beside the collagen content dermal collagen content(49.48±17.35).Conclusion Imiquimod may decrease the dermal thickness and collagen content histologically and suppress collagen synthesis and myofibroblasts production through downregulation of TIMP-1,PCNA and a-SMA and upregulation of MMP-1,respectively,immunohistochemically resulting in the improvement of scar index with measurement.