胰岛素样生长因子Ⅰ在生长激素促小肠代偿中的作用

The effects of insulin like growth factorⅠ on the intestinal adaptation in growth hormone-treated rats

目的 探讨胰岛素样生长因子Ⅰ (insulin likegrowthfactorⅠ ,IGFⅠ )在生长激素 (growthhormone ,GH)促小肠代偿中的作用。方法 将 2 0只SD大鼠随机分成GH组及STD组 ,建立PN短肠大鼠动物模型。用光镜检查小肠粘膜形态学变化 ,用放射性免疫分析法测定血GH及IGFⅠ浓度 ,用Northernblot法测定残存小肠IGFⅠmRNA表达。结果 GH组大鼠小肠粘膜厚度、绒毛高度及隐窝深度均显著高于STD组 ,分别为 (4 71± 16 ) μmvs.(374± 13) μm ,(2 99± 17) μmvs.(2 12± 19) μm及(16 1± 2 0 ) μmvs.(96± 9) μm ,P <0 0 1。血GH及IGFⅠ浓度在GH组显著高于STD组 ,分别为 (5 2±0 8)ng/mlvs.(3 3± 1 7)ng/ml及 (4 2 5± 19)ng/mlvs.(32 6± 30 )ng/ml,P <0 0 5 ,残存小肠形态学改变与血GH及IGFⅠ浓度变化间呈显著正相关。GH组小肠局部IGFⅠmRNA的表达显著高于STD组 (0 6 2± 0 0 4vs .0 41± 0 0 2 ) ,P <0 0 5。结论IGFⅠ在GH的促小肠代偿机制中起着重要的介导作用 ,全身性IGFⅠ增加及小肠局部IGFⅠ产生的增加均与小肠的代偿密切相关。

Objective To understand the effect of insulin-like growth factorⅠ (IGFⅠ) on the adaptation of the small intestine in growth hormone (GH)-treated rats. Method 20 SD rats were randomized into GH group and STD group. Parenterally fed, short bowel rat models were established. The morphological changes of the intestinal mucosal epithelia were examined, serum GH, IGFⅠ concentrations were determined by RIA method. The local intestinal IGFⅠ mRNA was evaluated by Northern blot method. Result At the end of the study, mucosal thickness, villous height, crypt depth in GH group (471±16, 299±17, 161±20 μm respectively) increased significantly compared to that in STD group (374±13, 212±19, 96±9 μm respectively, all P<001). Rats in GH group showed higher serum GH and IGFⅠ concentrations (52±08, 425±19 ng/ml respectively) than that in STD group (33±17, 326±30 ng/ml respectively, all P<005). The relative abundance of IGFⅠ mRNA in local small intestine was higher in GH group than in STD group (062±004 vs. 041±002 respectively, P<005). Conclusion IGFⅠ plays an important role in growth-promoting effects of GH in the adaptation of the remnant small intestine, the increase of the systemic IGFⅠ and the local IGFⅠ may both be responsible for this process.