Effect of 4-phenyibutyric acid on diabetic nephropathy rats / 中华肾脏病杂志

ABSTRACT

Objective To investigate the effect of 4-phenylbutyric acid(4-PBA)on the renal pathogenesis of rats with streptozotocin-induced diabetes and its mechanism. Methods Fifty-four male SD rats were randomly divided into three groupsnormal control group(NC group,n=18),diabetic nephropathy group(DN group,n=18),diabetic nephropathy plus 4-PBA treatment group(4-PBA group,n=18).At the end of 4,8 and 12 weeks,index of kidney weight/body weight ratio(KI)were measured and calculated.Serum creatinine (Scr),blood urea nitrogen(BUN),urinary MDA levels,urinary SOD activity,and 24 hour urinary protein excretion ram(UAER)were detected by HITACHI automatically.Morphology of kidney wag examined by special staining of periodic acid-schitt (PAS).The p47phox and nitrotyrosine (NT) expression in kidney were determined by real-time fluorescence PCR and Western blotting. Results Compared with the NC group, the DN group rats showed a significant increase of KI(P＜0.05), UAER(mg/24 h) (4.92±0.70 vs 0.26±0.07, 5.29±0.83 vs 0.28±0.08, 5.54±0.81 vs 0.29±0.04,respectively, P＜0.05]for indicated time, mesangial cells proliferation and mesangial matrix expansion at 12 week. However,4-PBA treatment could significantly inhibit the increase of KI (P＜0.05), decrease UAER (mg/24 h) (3.71±0.37, 3.47±0.36, 3.28±0.40, respectively, P＜0.05]for indicated time, and prevent the glomeruler pathological alteration induced by diabetes. Moreover, the mRNA expression of p47phox in the kidney of DN group was 154.72%, 148.60% and 91.95% more than that of NC group (all P＜0.05) for indicated time. The protein expression of p47phox was 118.00%, 140.10% and 177.82% more than that of NC group (all P＜0.05), and the protein expression of NT was 45.29%,59.13% and 89.28% more than that of NC group (all P＜0.05). In addition, urinary MDA levels in DN group were 2.05-, 2.26- and 2.43- folds of NC group, and urinary SOD activities were decreased by 64.78%, 71.29% and 79.32% of NC group. Compared with the DN group, the mRNA and protein expression of p47phox, and protein expression of NT in 4-PBA group were decreased markedly (all P＜0.05) at the end of 8 and 12 weeks. The urinary MDA level was decreased, and the urinary SOD activity was increased significantly in rats with diabetes after 4-PBA treatment for indicated time (all P＜0.05). Conclusion 4-PBA treatment can significantly inhibit the renal pathogenesis of rats with diabetes through inhibition of oxidative stress.