大豆分离蛋白对大鼠阿霉素肾病模型稳定性的影响

Soy protein isolate improves the stability of rat adriamycin nephropathy

目的:观察大豆分离蛋白对大鼠阿霉素肾病模型稳定性的影响。方法:70只大鼠随机分为对照组(n=7)、普通饲料组(n=31)和高蛋白饲料组(n=32)。普通饲料组和高蛋白饲料组大鼠分两次通过尾静脉注射阿霉素造模,对照组大鼠注射等量的生理盐水。从首次注射阿霉素起,高蛋白饲料组大鼠给予两周含有20%大豆分离蛋白的饲料,之后改为普通饲料;对照组和普通饲料组则始终给予普通饲料。造模18 d后,比较3组大鼠的存活率和24 h尿蛋白总量(24 h Pro)。造模前,造模24、31、38、45和52 d,测定对照组和高蛋白饲料组大鼠24 h Pro、后肢足掌厚度、血清白蛋白(ALB)和尿素氮(BUN)水平。实验结束时,取肾脏组织行透射电子显微镜观察和过碘酸雪夫染色(PAS)。结果:给予两周高蛋白饲料喂养后,阿霉素肾病大鼠的存活率由普通饲料组的50%提高到100%;普通饲料组和高蛋白饲料组大鼠的24 h Pro分别为(115.6±84.0)和(33.5±3.6)mg,均高于对照组(7.1±1.4)mg(P<0.05)。高蛋白饲料组大鼠在造模24 d出现高蛋白尿、水肿和低蛋白血症,造模45 d出现血清BUN的升高。造模24 d,高蛋白饲料组大鼠光镜下肾小球未见病变,电镜下发现足突部分融合,有微小病变型肾病的症状;实验结束时PAS显示肾小球基底膜节段增厚,球囊粘连,呈现显著的肾小球节段性硬化。结论:给予两周含有20%大豆分离蛋白饲料的大鼠阿霉素肾病模型建模成功率高,动物之间病变差异小,重复性和稳定性好,并可动态观察肾病的发展过程。

Aim：To investigate the effects of soy protein isolate on rat adriamycin（ADR）nephropathy model.Methods：Seventy rats were randomly allocated into control group（group A,n=7）,normal diet group（group B,n=31）high protein diet group（group C,n=32）.The rats of group B and group C were intravenously injected ADR twice at 4.0 and 3.5 mg/kg,respectively with one week interval,and the rats of group A were given corresponding dose of normal saline.Immediately after the first ADR administration,rats of group C were fed with high protein diet（20% soy protein isolate being added to the normal diet）for 2 weeks,while the other two groups were given normal diet from the beginning to the end.After 20 d,the survival rate and 24 h urine protein（24 h Pro）in the 3 groups were assessed.Then 24 h Pro,the thickness of hind paws,the levels of serum albumin and urea nitrogen（BUN）were assessed before modeling,24,31,38,45 and 52 d after modeling in group A and C.At the end of the experiment,the kidneys were studied by periodic acid-Schiff staining to evaluate the pathology changes.Results：The survival rate of group C was 100%,much higher than that in group B（50%）.The 24 h Pro in group B and group C was（115.6±84.0）mg and（33.5±3.6）mg,higher than that in group A[（7.1±1.4）mg]（P〈0.05）.Besides,24 d after the initial ADR injection,the rats in group C developed high proteinuria,edema,and hypoproteinemia;there was no histological abnormality in the glomerular under light microscope,however,partial fusion of foot process could be seen under penetrating electric microscope;45 d after the initial ADR injection,the rats in group C developed high BUN.PAS staining showed that glomerular basement membrane segment thickened,and saccule adhesion and focal segmental glomerulosclerosis also could be seen.Conclusion：Adding 20% soy protein isolate to the normal diet for 2 weeks assists to establish a stable and reproducible rat ADR nephropathy model,which favours the dynamic observation of the pathogenetic nephropathy.