The Effect Of Simvastatin And Losartan On The Expression Of Nephrin Gene Of Diabetic Glomerulopathy In STZ-induced Diabetic Rats

Objective: To study the effect of 3- hydroxy-3- Methylglutaryl CoA inhibitor Simvastatin and specific antagonist of angiotensin II receptor Losartan on the expression of nephrin gene of diabetic glomerulopathy in STZ-induced diabetic rats.Methods: Adult male SD rats were divided randomly into 9 groupsxontrol group and the groups of 2 weeks after injected STZ, 4 weeks after injected STZ, 4 weeks after DM no treated, 8 weeks after DM no treated, 4 weeks after treated with Losartan, 8 weeks after treated with Losartan, 4 weeks after treated with Simvastatin and 8 weeks after treated with Simvastatin. The rats were induced to become diabetes by injection of STZ. The last four groups were treated orally with Simvastatin and Losartan differently. The rats of each group were sacrificed in different process of diabetes, then urinary albumin excretion (UAE), urinary β2-MG excretion, plasma cholesterol, quantity of the expression of nephrin gene were measured.Results: The UAE and urinary β2-MG excretion rates of DM no treated groups were higher than control group, and these two rates of all groups treated with Simvastatin or Losartan were much lower than 8 weeks after DM no treated group. The quantity of the expression of nephrin gene in 4 weeks after injected STZ group were two times higher than control group, and the quantity of expression of this gene in all the DM no treated groups were much lower than control group, 4 weeks after injected STZ group and 8 weeks after treated with Losartan group, specially, 8 weeks after DM no treated group not only lower than the three groups above, but also lower than all the Simvastatin treated groups; group after treated with Losartan 8 weeks was higher than 4 weeks treated with Losartan, but there is no differencebetween 4 weeks after treated with Simvastatin group and 8 weeks after treated with Simvastatin.Conclusion: The UAE and the urinary β2-MG excretion rates were higher in diabetic rats, and both Simvastatin and Losartan can reduce these two rates in diabetic rats; after injected STZ 4 weeks, the quantity of nephrin gene which express on the kidney of diabetic rats increases 50 percent, nevertheless the quantity began to decrease with the prolonging of the time of high blood sugar; both Simvastatin and Losartan can hold off this descending of nephrin gene expression.