The antinephritic effect of lipo-prostaglandin E1 prostaglandin E1 incorporated in lipid microspheres was investigated using an experimental model of mesangial proliferative glomerulonephritis (MsPGN). Twenty-two female rats were randomly divided into nephritic group (N, n = 6), lipo-prostaglandin E1 treated group (NL, n = 8) and control group (C, n = 6). Lipo-prostaglandin E1 was given intravenously at 40 microg x kg(-1) x d(-1) from the 6th week to the 8th week. Twenty-four h urinary protein contents and blood creatinine (Cr) were determined and the pathological changes were observed in the experiment. The expression of proliferating cell nuclear antigen (PCNA), extracellular matrix (fibronectin, FN; collagen type IV, Col IV) and transforming growth factor beta1 (TGFbeta1) was detected by using immunohistochemistry. The results showed that lipo-prostaglandin E1 significantly inhibited the glomerular histopathological changes as well as the elevation of plasma Cr (P < 0.05). The overexpression of PCNA, FN, Col IV and TGFbeta1 were also obviously inhibited in group NL as compared with the group N (P < 0.01). It was suggested that lipo-prostaglandin E1 could improve renal function, inhibit the proliferation of glomerular cells and reduce the deposition of extracellular matrix, which may be related to the down-regulation of the TGFbeta1 expression.