牛初乳短链胰岛素样生长因子-1对多柔比星肾病大鼠胰岛素样生长因子-1的影响

Effect of Bovine Colostrum Truncated Insulin Like Growth Factor-1 on Insulin Like Growth Factor-1 in Rats with Adriamycin-Induced Nephropathy

目的研究牛初乳短链胰岛素样生长因子-1(BctIGF-1)对肾病大鼠胰岛素样生长因子-1(IGF-1)的影响,为治疗肾病综合征(NS)提供理论依据。方法将30只周龄相同、体质量相近的雌性SD大鼠随机分为对照组、肾病组、BctIGF-1治疗组;实验第6周末杀鼠,采用放射免疫法测定其血清与尿IGF-1水平,反转录酶-聚合酶链反应(RT-PCR)测定其肝、肾组织IGF-1 mRNA表达,采用考马斯亮蓝法测定24h尿蛋白排泄量。结果BctIGF-1治疗组24h尿蛋白及病理积分均低于肾病组(P<0.05,0.01);肾病大鼠血清IGF-1水平明显低于BctIGF-1治疗组(P<0.05),尿IGF-1排泄量明显高于BctIGF-1治疗组(P<0.01);各组大鼠肝组织IGF-1 mRNA表达差异无显著性;肾组织IGF-1mRNA表达由高至低依次为对照组、BctIGF-1治疗组、肾病组,BctIGF-1治疗与对照组比较差异无显著性,但BctIGF-1治疗与对照组IGF-1 mRNA表达均显著高于肾病组(P<0.01,0.05)。结论BctIGF-1可有效降低肾病大鼠尿蛋白,减轻肾脏病理损伤,其机制可能是通过增加其血清游离IGF-1水平、促进肾局部IGF-1mRNA表达来实现。

Objective To observe the effect of the bovine colostrum truncated insulin-like growth factor-1（BctIGF-1）to insulin like growth factor-1（IGF-1）of the rats with adriamycin-induced nephropathy and provide theoretical bases for the clinical application of BctIGF-1 to the renal disease.Methods Thirty female SD rats with the same age and similar weight were divided into control group,nephro-tic group and BctIGF-1 group and were killed 6 weeks after the experiment.The IGF-1 level in serum and urine was determined by radio-immunity assay,the mRNA expression of IGF-1 in liver and kidney was determined by reverse transcriptase-polymerase chain reaction（RT-PCR）assay and the protein excretion from 24 hours urine was detected by Coomassie brilliant blue.Results At the end of the experiment,the protein excretion from 24 hours urine and the histopathological score of glomeruli in BctIGF-1 group were lower than those in nephrotic group（P〈0.05,0.01）,and the rats in nephrotic group got a lower lever of the serum IGF-1 than those in BctIGF-1 group（P〈0.05）,while the urinary IGF-1 excretion from nephrotic group was higher than that of BctIGF-1 group（P〈0.01）.No difference was found in the expression of IGF-1 mRNA in liver from the rats of all the groups.Expression of IGF-1 mRNA in kidney was the highest of control group,and the lowest of nephrotic group,with no difference between control group and BctIGF-1 group.But expression of IGF-1 mRNA in kidney of control group and BctIGF-1 group significantly higher than nephrotic group（P〈0.01,0.05）.Conclusion BctIGF-1 can decrease the urinary protein excretion and retard the renal damage,probably due to its effects on increasing the serum free IGF-1 level and promoting the expression of mRNA in kidney.