生长激素对阻塞性黄疸大鼠肠黏膜的保护作用及机制

目的 研究生长激素(GH)对阻塞性黄疸大鼠肠黏膜的保护作用和机制。方法 将大鼠随机分为假手术组、胆总管结扎组和胆总管结扎 生长激素组3组。两周后测定3组大鼠门静脉和体静脉血液的内毒素水平；对肠系膜淋巴结(MLNs)和肝脏进行细菌培养；用RT-PCR测定肠粘膜胰岛素样生长因子-1(IGF-1)mRNA的表达水平；取末端回肠组织观察肠黏膜病理变化。结果 胆总管结扎两周后大鼠发生内毒素和细菌移位，肠黏膜正常结构受损。使用GH后肠黏膜IGF-1 mRNA表达水平增高，上述病变显著减轻。结论 阻塞性黄疸使大鼠肠黏膜屏障功能受损，使用GH可上调IGF-1 mRNA的表达，对阻黄大鼠肠黏膜起保护作用。

The Protective Effects and Mechanism of Growth Hormone on the Ileal Mucosa in Jaundiced Rats

Objective To study the protective effects and mechanism of human growth hormone (GH) on the ileal mucosa in bile duct ligated rats. Methods Fifty-two Wistar rats were randomly assigned to three groups: sham operated (SO), bile duct ligated (BDL), and BDL combined with GH treated. Two weeks after the operation all rats were sacrificed and the following items were tested: (1) the concentration of endotoxin in portal and systemic blood; (2) the bacteria of mesenteric lymph nodes and livers; (3) insulin-like growth factor-1 (IGF-1) mRNA expression of the distal ileal mucosa; (4) the morphological changes of the ileal mucosa under microscope and electron-microscope. Results The translocation of bacteria and endotoxin occurred and the pathological change was observed two weeks after BDL. Treatment with GH significantly reduced bacteria and endotoxin translocation from the gut and ameliorated the ileum mucosa. The expression of IGF-1 mRNA in ileal mucosa was markedly decreased after BDL and could be reversed by GH administration. Conclusion Obstructive juandice could result in the impairment of ileum mucosa in rats and the GH treatment showed protective effects through up-regulation of IGF-1 mRNA in ileum.