Abstract:

Objective This study was carried out to investigate the role of the RAS in the early stage of IgA nephropathy with the aim of providing experimental basis for clinical selection of appropriate drugs.Methods There were 38 biopsy-proven primary IgA nephropathy(IgAN) patients.According to the degree of mesangial proliferation,we divided them into two groups: the groupⅠ of mild mesangial proliferation was to be designated as early IgAN group,the groupⅡ of moderate and severe mesangial proliferation was to be designated as progressive IgAN group.Subjects for normal control group were taken from normal portions of renal cell carcinoma at the time of surgery.Immunohistochemistry methods were used to study the expression of angiotensin Ⅱ(AngⅡ),angiotensin type 1 receptor(AT₁R),transforming growth factor-β1(TGF-β1),and the detection of AT₁R mRNA by in situ-hybridization on the paraffin-embbedded sections.The percentage of the labeled surface area was evaluated by using a computer Imaging System.Results In normal kidney,AngⅡ AT₁RmAT₁RmRNA and TGF-β1 are all expressed tracely,in samples from early IgAN patients,a marked increase of the expressions was observed.On the glomerules,AngⅡ expression was significantly higher in progressive group than early IgAN group(P=0.032).There were complex correlations among the factors.Conclusion The renal local AngⅡ had been activated in the early stage of IgA nephropathy. The earlier use of RAS inhibitors may inhibit the progress of IgA nephropathy.

Key words: IgA nephropathy, angiotensin Ⅱ, angiotensin Ⅱ type 1 receptor, renin-angiotensin system, transforming growth factor-&beta, 1