OBJECTIVETo study the expression of TGF-beta(1)vimentin and desmin in the renal cortex of diabetic rats induced by STZ.

METHODSDiabetes was induced in 24 male SD rats by single intraperitoneal injection of 1.0%STZ (70 mg/kg). Twenty-four age, weight and sex matched SD rats were used as controls. The expression of TGF-beta(1),vimentin and desmin mRNA in the renal cortex were detected by RT-PCR on the 3rd, the 7th, the 14th and the 30th day after the DM rat model established.

RESULT(1)The expression of TGF-beta(1), vimentin mRNA in the renal cortex of diabetic rats gradually increased respectively from the 7th day and the 14th day after the model established, and the expressive intensity was significantly greater than that in controls (P<0.05 or P<0.01). However,the expression of desmin mRNA in the renal cortex of diabetic rats gradually decreased from the 14th day after the model established, and the expressive intensity was significantly less than that in controls (P<0. 05 or P<0.01). (2) The expression of TGF-beta(1)mRNA correlated positively to that of vimentin mRNA (r 0.740 P=0.000), while the expression of desmin mRNA correlated negatively to that of TGF-beta(1)mRNA (r 0.695 P=0.000) and to that of vimentin mRNA (r 0.591 P=0.002).

CONCLUSIONThe expression of renal cortical TGF-beta(1) and vimentin mRNA gradually increase while the expression of desmin mRNA gradually decrease during the first month of the diabetic model established suggest TGF-beta(1) may play a role in the transformation of renal tubular epithelial cells into fibroblast during the progressive interstitial fibrosis of diabetic nephropathy.