Effect Of Gypenosides On The Expression Of Nephrin,VEGF In The Kidney Of Diabetic Nephropathy Rats

Objective To discuss the effect of gypenosides(GP) on reducing the urine protein and the mechanism of kidney protection. Watching the expression of nephrin and vascular endothelial growth factor(VEGF) in the kidney of diabetic nephropathy(DN) rats, make a research about the gypenosides effect on the expression of these two targets.Methods Randomly selected 50 male Sprague-Dawley(SD) rats of clean levels among 60 rats. The mode of DN was produced by unilateral nephrecotomy and injection of streptozocin(STZ). DN rats were randomly divided into 5 groups by blood sugar:high-dose GP group(A:1g/kg),moderate-dose GP group(B:0.5g/kg),low-dose GP group(C:0.25g/kg),valsartan group(D:8mg/kg),DN group(E). The other 10 rats formed control group (F). The 0.9% physiological saline was given to group E and F. After the treatment for 4 weeks, check out the kidney function,24h urine volume and 24h urinary protein, measure the glomerular hypertrophy. The ultrastructure of glomerulus were observed by electron microscope. And the mRNA expression of nephrin,VEGF was detected by RT-PCR. The expression of nephrin,VEGF protein was examined by Immunohistochemistry.Results 1.Other groups compared with group F:The foot process width(FPW) and thickness of glomerlar basement membrane(GBM) was increased. Some foot processes were fusioned into a band. The expression of nephrin mRNA and protein in the kidney were both significantly reduced(P<0.01),while the expression of VEGF mRNA and protein were increased (P<0.01);24h urine volume,24h urinary protein count,blood urea nitrogen(BUN) and serum creatinine (SCr) were significantly increased(P<0.05).2. other treatment groups compared with group E:â‘ FPW and GBM decreased. The expression of nephrin mRNA and protein were both significantly increased (P<0.01), whereas the expression of VEGF mRNA and protein were decreased (P<0.05). The effect of group A and group D were superior to group C (P<0.05). What's more, There was no difference between group A and group D(P>0.05).â‘¡The levels of 24h urine volume,24h urinary protein count,BUN,SCr all significantly decreased in group A and group D(P<0.05). And that, there was no difference between group C and group E in the above indexes(P>0.05).3.24h urinary protein count was negative correlated with the levels of nephrin mRNA and protein (r=-0.685,P<0.01; r'=-0.667,P'<0.01).While, it was positive correlated with the levels of nephrin mRNA and protein (r=0.684,P<0.01; r'=-0.621,P'<0.01). Moreover, there was a negative relationship between the levels of nephrin,VEGF mRNA and protein.Conclusion 1. The structure and function of podocyte damage exists in Diabetic nephropathy, and it plays an important role in albuminuria occurrence and development.2. GP may up-regulate nephrin expression and down- regulate VEGF expression, alleviate podocyte ultrastructural changes and protect the kidney and reduce the urinary protein.3. Different doses of GP have different effects.The high-dose GP group has more significant effect than the low-dose GP, and the effect is similar to the valsartan group.