Objective:To explore the effects of 1

25-dihydroxyvitamin D3 on renal expression of TGF-β1 and HGF in type 1 diabetic rats.Methods:30 Sprague-Dawley rats were randomized into 3 groups:normal control rats(group NC)

diabetic rats(group DM ) and diabetic rats treated with 1

25-dihydroxyvitamin D3(group DC).Kidney-to-body weight ratio(KW/BW)

mean glomerular volume(MGV)

fractional mesangial area(FMA)

urinary albumin excretion rate(UAER)and serum creatinine(Scr)were measured after 12 weeks of treatment

while transforming growth factor-betal(TGF-β1) expression in kidney cortex were observed by immunohistochemistry.The expression levels of TGF-β1 mRNA and HGF mRNA were detected by reverse transcription and polymerase chain reaction(RT-PCR) at the end of the experiment.Results:UAER

Scr

MGV

FMA and KW/BW ratio were significantly higher in the diabetic rats than those in the normal control rats(P<0.05).The expression levels of TGF-β1 and HGF in the diabetic rats were also higher as compared with those in the normal control group(P<0.05).UAER

Scr

MGV

FMA and KW/BW ratio and the expression levels of TGF-β1 in the 1

25-dihydroxyvitamin D3-treated group were obviously lower than those in the diabetic rats(P<0.05)

while the levels of HGFmRNA in the 1

25-dihydroxyvitamin D3-treated group were obviously higher than in diabetic rats.Conclusion:1

25-dihydroxyvitamin D3 has some renal protective effect on diabetes in rats

partly by down-regulating TGF-β1 and up-regulating HGF expressions in renal cortex。