几丁糖预防腹膜粘连抑制胶原基因表达的实验研究

Role of chitosan in collagens gene expression and prevention of postoperative adhesion

目的 :探讨几丁糖在胶原基因表达及预防大鼠腹膜粘连形成中的作用。方法 :制作大鼠回肠浆膜均一缺损的腹膜粘连模型 ,关腹前注入乳酸Ringer液或几丁糖 ,术后 14天进行粘连评分。采用半定量逆转录 -聚合酶链反应 (RT PCR)方法测定各粘连组织标本Ⅰ型胶原基因mRNA的表达 ;采用苦味酸天狼猩红染色 -偏振光法及计算机图像分析系统来观察和分析Ⅰ型和Ⅲ型胶原纤维在粘连组织中的分布及染色表达面积。结果 :与正常腹膜和乳酸Ringer’s液组相比 ,几丁糖组大鼠的粘连显著减轻 ,Ⅰ型胶原基因mRNA的表达减弱 ,Ⅰ型胶原形成减少 (P <0 .0 1) ,Ⅲ型胶原在各组间无差别 (P >0 .0 5 )。结论 :胶原基因的过度表达可能在粘连形成过程中有重要的作用 ,几丁糖能抑制Ⅰ型胶原基因的表达 ,减少Ⅰ型胶原的合成 。

Objective:To investgate the role of chitosan in gene expression of collagen and peritoneal adhesion formation.Methods:The uniform defects on cecal surface were developed to establish the adhesion model of rats.Prior to the closure of the abdomen,Lactate Ringer's salution or chitosan was instilled into the abdominal cavity of the Lactate Ringer's salution group or the chitosan group,respectively.The severity of adhesions was graded by a blinded observer two weeks after operation.The mRNA expression of type Ⅰ collagens in the intact peritoneum and adhesive tissues was detected using reverse transcription polymerase chain reaction(RT PCR) technique.Picrosirius polarization method and digital image analysis were used to detect the distribution of collagen fiber in adhesive tissues.Results:Collagen typeⅠgene in adhesive tissues in the laitate Ringer's group showed a significantly increased mRNA expression as compared with that in the intact peritoneal in the nomal control group( P <0.01).The chitosan group had significantly milder adhesions than the laitate Ringer's group.The mRNA expression of collagen typeⅠ gene in adhesive tissues in chitosan group(0.75±0.22) was significantly decreased as compared with that in the Ringer's salution group( P <0.001).The area of collagen type Ⅰ in the chitosan group was smaller than in the laitate Ringers' salution group( P <0.01).The difference in the area of collagen type Ⅲ was not significant among all the groups( P >0.01).Conclusions:Upregulation of collagen typeⅠsynthesis appears to play a critical role in the pathophysiology of postoperative adhesion.Chitosan can prevent the increase in collagens typeⅠgene expression and collagen content after adhesion induction.