部分肝切除后大鼠结肠黏膜层超微结构的变化

目的 探讨部分肝切除(PH)对大鼠结肠黏膜层超微结构的影响.方法 选取健康SD大鼠35只,分为1个正常对照组、3个假手术(SO)对照组和3个2/3 PH组,正常对照组大鼠直接处死,SO组和PH组大鼠分别于术后6、12和24 h处死,均取结肠固定后超薄切片,透射电镜下观察结肠黏膜层超微结构的变化.结果 与正常对照组相比,SO组大鼠结肠黏膜层超微结构无明显变化.PH 6和12 h组结肠黏膜层超微结构发生了较明显变化:微绒毛萎缩,上皮细胞间隙增大,杯形细胞线粒体损伤,内分泌细胞分泌增强,肥大细胞脱颗粒明显,巨噬细胞吞噬活跃,中性粒细胞富集.PH 24 h组,内分泌细胞仍然活跃,其他变化不明显.结论 PH后结肠黏膜屏障结构破坏,易发生感染;内分泌细胞和肥大细胞等活化,有利于残肝的修复和再生.

Changes of the ultrastructure of colon mucosa after partial hepatectomy in rats

Objective To study the effects of partial hepatectomy (PH) on the ultrastructure of colon mucosa in rats. Methods Thirty-five healthy SD rats were divided into one normal control group, three sham-operation (SO) control groups and three operation (2/3 PH) groups. The rats in the SO and PH groups were sacrificed at the 6th, 12th and 24th hour after speration). The colon was collected and prepared as ultrathin sections. Samples were observed by transmission electron microscope (TEM). Results Compared with that in the normal control group rats, the ultrastructure of colon mucosa did not show distinct changes in the SO groups. However, significant changes were observed in PH 6- and 12- hour groups rats, for example, the microvilli became short, enterocyte interspace was greatly increased, mitochondria of goblet cells was impaired, endocrine cells were stimulated, degranulation of mast cells was marked, macrophages were filled with phagosomes, neutrophilic granulocytes were gathered to lamina propria. In PH 24-hour groups, endocrine cells were still active, but other changes were not evident. Conclusion After PH, colon mucosa barrier is acutely damaged which leads a rising rate of infection. However, stimulation of endocrine cells and mast cells may be helpful to liver regeneration and recovery.