维生素C对糖尿病肾病大鼠Ⅳ型胶原α_1mRNA表达的影响

Effect of vitamin C on the expression of collagen alpha 1 mRNA in rats with diabetic nephropathy

目的:观察维生素C对糖尿病肾病大鼠Ⅳ型胶原α1mRNA表达及肾脏功能的影响。方法:实验于2004-01/04在南华大学动物部完成。大鼠预养1周后,空腹12h,腹腔注射60mg/kg链尿佐菌素-柠檬酸钠缓冲液,对照组注射等量柠檬酸钠缓冲液,依据72h后尿糖～,静脉采血测血糖≥16.7mmol/L,确定建立Ⅰ型糖尿病大鼠模型。将SD大鼠随机分为正常对照组、糖尿病组和维生素C组,保持大鼠血糖波动在25mmol/L左右,持续16周。观察治疗期间及治疗后大鼠的一般状况、血糖、尿素氮、血肌酐,内生肌酐清除率、24h尿蛋白排泄率,原位杂交检测肾组织Ⅳ型胶原α1基因表达。结果:30只SD大鼠实验过程中无死亡,全部纳入结果分析。①大鼠体质量较正常对照组明显下降,尿量增加,血糖升高,差异有显著性意义(t=4.945,3.779,P<0.05),治疗后维生素C组与糖尿病组相比,体质量、肾质量/体质量有显著提高(t=2.927,3.032,P<0.05)。②大鼠血清尿白蛋白排泄率、血肌酐、尿素氮较正常对照组明显升高,内生肌酐清除率下降,有显著性差异(t=4.113,3.1251,2.798,P<0.05),糖尿病组与维生素C组相比,尿白蛋白排泄率、血肌酐、尿素氮明显升高,内生肌酐清除率下降(t=2.875,2.994,3.102,P<0.05)。③与正常对照组相比,肾小球血管细胞外基质Ⅳ型胶原α1基因表达显著上调,经灰度值测定两组间差异有显著性意义(P<0.05,t=4.766),治疗后维生素C组肾组织着色浅淡稀疏,与糖尿病组相比Ⅳ型胶原α1基因相对表达明显下调(t=2.879,P<0.05)。结论:维生素C无降糖作用,但具有确切的肾脏保护作用。

AIM： To observe the Effect of vitamin C on the expression of Collagen Ⅳ α1 mRNA and renal function in rats with diabetic nephropathy. METHODS： The experiment was carried out in the animal section of Nanhua University from January to April 2004. The rats were fasted for 12 hours after 1-week pre-feeding, and then they were treated with intraperitoneal injection of 60 mg/kg streptozotocin-citromalic acid buffer and citromalic acid buffer of the same volume （control group） respectively to establish models of type 1 diabetes mellitus according to the standards that uric glucose after 72 hours was to , and the venous blood glucose was ≥16.7 rmnol/L. The SD rats were randomly divided into normal control group, diabetic group and vitamin C group, and the fluctuation of blood glucose was kept around 25 rmnol/L for 16 weeks. During and after the treatment, the general state, blood glucose levels, blood urea nitrogen, serum creatinine, clearance rate of creatinine, and 24-hour urinary albumin excretion rate were observed, and the type the gene expression of coliage Ⅳ α1 gene in the kidney tissue was determined by in situ hybridization analysis. RESULTS： All the 30 SD rats were involved in the analysis of results without death. ① As compared with the normal control group, the body mass was obviously decreased, uric amount was increased, blood glucose was elevated, and there were significant differences （t=4.945, 3.779, P 〈 0.05）. After treatment, the body mass and renal mass/body mass in the vitamin C group were significantly increased as compared with those in the diabetic group （t=2.927, 30.32, P 〈 0.05）. ②As compared with the normal control group, the serum urinary albumin excretion rate, serum creatinine and blood urea nitrogen were obviously increased, and clearance rate of creatinine was significantly decreased （t=4.113,3.125 1,2.798,P 〈 0.05）. Compared the diabetic group with the vitamin C group, the serum urinary albumin excretion rate, serum creatinine and blood urea nitrogen were obviously increased, and clearance rate of creatinine was decreased （t=2.875, 2.994,3.102, P 〈 0.05）. ③ As compared with the normal control group, the expression of renal glomerular extracellular matrix collage Ⅳ α1 gene was significantly up-regulated, and the determination of gray value showed significant differences between the two groups （t=4.766, P 〈 0.05）; After treatment, the pigmenting of renal tissue was light and sparse, and the relative expression of collage Ⅳ α1 gene was obviously down-regulated as compared with that in the diabetic group （t=2.879, P 〈 0.05）. CONCLUSION： Vitamin C has no effect in decreasing the level of blood glucose, but plays a certain role in protecting kidney.