Experimental Study On The Mechanism Of Valsartan Effect On Diabetic Nephropathy

[OBJECTIVE]To observe the effect of valsartan on glomerular mesangial cells oxidative stress induced by high glucose, study the effect of valsartan on the matrix deposition in mesangial cell induced by high glucose, expecting to elucidate the preliminary mechanism of action of valsartan in diabetic nephropathy.[METHODS] 1. Mesangial cell was cultured in high glucose and intervened by valsartan of different concentration. The mRNA of p22phox, which was the primary subunit of NADPH oxidase, was detected by semi-quantitative reberse transcription polymerase chain reaction (RT-PCR). The Reactive Oxygen Species (ROS) in cells was measured by Flow cytometry, using DCFH-DA and HE label, in order to observe the effect of valsartan on glomerular mesangial cells oxidative stress induced by high glucose, 2. Mesangial cell was cultured in high glucose and intervened by valsartan of different concentration. Fibronectin(FN),plasminogen activator inhibitor-1(PAI-1),matrix metalloproteinases-2(MMP-2),tissue inhibitor of metalloproteinase-2(TIMP-2) reflected the matrix deposition, was detected by RT-PCR, (transforming growth factor-β1)TGF-β1, as an important fator on matrix deposition, was detected by ELISA, in order to investigate the valsartan's effect on the matrix deposition.[RESULTS] 1. The expression of p22phox mRNA was not increased cultured in high glucose for 2 days, and there were no difference on the groups intervened by valsartan. Till the mesangial cells were cultured in high glucose for 5 days, the expression of p22phox mRNA was increased, and the effect was inhibited by valsartan, the inhibitory effect had dose dependent effect. The expression of .O2- and H2O2 was up-regulated with glucose concentration and the effect was inhibited by valsartan. 2.High glucose induced the up-regulation of FN,PAI-1,TIMP-2 mRNA,TGF-β1 protein and the down-regulation of MMP-2 mRNA, valsartan could normalize them, having a dose dependent effect.[CONCLUSIONS] 1. Valsartan could inhibit the up-regulated of oxidative stress induced by high glucose, and it had dose dependent effect. 2. Valsartan could inhibit the up-regulated of matrix deposition induced by high glucose, and the inhibition had dose dependent effect.