['To investigate the effects of leukemia inhibitory factor (LIF) on renal interstitial fibroblast activation following induction by transforming growth factor beta 1 (TGF-beta1).', 'Normal rat interstitial fibroblast cells (NRK/49F) were treated with TGF-beta1 and TGF-beta1, combining with LIF respectively for different duration with different concentration. Changes in cell morphology and expression of alpha-SMA were evaluated with electronic microscope and Western blot respectively. The collagen I in the supernatant was detected with ABC-ELISA.', 'TGF-beta1 induced renal interstitial fibroblast activation, and this was accompanied by significant morphological transformations and secretion of collagen I. Co-culturing of cells with LIF blocked the morphological transformation. In addition, LIF inhibited TGF-beta1-induced expression of alpha-SMA mRNA and protein (P < 0.01), and decreased the levels of collagen I (P < 0.01) in a dose-dependent manner.'] Does [ Leukemia inhibitory factor suppress renal interstitial fibroblast activation induced by transforming growth factor ]?