脑出血模型大鼠脑组织胰岛素样生长因子-1表达的实验研究

目的：观察脑出血模型大鼠脑组织胰岛素样生长因子-1（IGF-1）的表达及其对细胞凋亡的影响。方法随机将105只大鼠分为正常对照组、假手术组及脑出血组，应用立体定向技术，将自体未抗凝血注入大鼠基底节区制备脑出血模型；分别在造模后6、24、48、72h和1周将大鼠断头取脑制作标本，采用TUNEL染色检测脑组织细胞凋亡、荧光定量RT-PCR检测IGF-1 mRNA表达，免疫组化分析IGF-1表达。结果脑出血后6h血肿周围脑组织IGF-1及TUNEL染色阳性细胞表达升高，其中IGF-1在24h达高峰，48h开始下降，而细胞凋亡于72h达高峰，1周开始下降，表达均明显高于假手术组和正常对照组（P〈0.05，P〈0.01）；且IGF-1表达与细胞凋亡数呈正相关（P〈0.05）。结论脑出血后IGF-1表达上调，参与了脑出血的病理生理过程，可能对脑出血继发神经损伤起重要的保护作用。

Expression of IGF-1 in Rats with Intracerebral Hemorrhage

To investigate the expression of insulin-like growth factor-1 （IGF-1） in brain tissue of rats with experimental intracerebral hemorrhage and its effect on apoptosis. Methods One hundred and five rats were randomly divided into normal control group （n=5）,sham-operated group （n=50）,and intracerebral hemorrhage group （n=50）. Intracerebral hemorrhage was induced by stereotaxic injection of autologous blood into right caudate nucleus of rats. Rats were sacrifice at 6,24,48,72h and 1 week after the establishment of animal models,respec-tively. TUNEL method was used to detect apoptosis. Both of RT-PCR and immunohistochemistry were used to de-tect the expression of IGF-1 in brain tissues. Results The expression of IGF-1 and TUNEL-positive cells in per-i-hematomal brain tissue started to increase at 6h;the expression of IGF-1 peaked at 24h and began to decrease at 48h;apoptosis peaked at 72h and began to decrease at 1 week. The expression of IGF-1 and TUNEL-positive cells were higher than those in sham-operated group and normal control group at each time point （P〈0.05 or P〈0.01）. IGF-1 expression was positively related with apoptosis cells（P〈0.05）. Conclusion The expression of IGF-1 in brain tissue was up-regulated after intracerebral hemorrhage. It participates in the pathophysiologic course of in-tracerebral hemorrhage and has protective effect against secondary neuronal injury.