Objective Fibrin deposition combined with glomerular epithelial cell proliferation and monocyte/macrophage infiltration is involved in the pathogenesis of crescentic glomerulonephritis and results from local thrombin generation.In addition to its effect on procoagulation and fibrinolysis,thrombin exerts many cellular effects through a functional thrombin receptor,protease-activated receptor-1(PAR-1).The paper is To determine the role of PAR-1 in the pathogenesis of crescentic glomerulonephritis.Methods wild type and PAR-1 knockout mice in an accelerated model of anti-glomerular basement menbrane antibody nephritis were studied.Results The wild type mice exhibited severe glomerular injury 10 days after injection of sheep anti-mouse glomerular besement membrane antibody,such as thrombus formation,extracapillary proiferation as well as renal failure.APR-1 knockout mice showed significant protection from crescentic glomerulonephritis.Conclusion PAR-1 plays a critical role in the pathogenesis of crescentic glomerulonephritis and may be a new target for therapeutic intervention.