Objective: To explore the effect of specific cyclooxygenase-2 inhibitor(Rofecoxib) on the expression of plasminogen activator inhibitor type-1 in MRL/lpr mice.Methods: 12-week female MRL/lpr mice were given Rofecoxib[10mg/(kg·d)] for 12 weeks.Changes in proteinuria

serum creatinine and pathology in renal were observed.Suppressive effect of the drugs on angiotensin II and urinary thromboxane B2 and 6-Keton-prostaglandin-F1α were determined by using radio-immunological assay.Immunolhistological analysis was used to examine the expression of PAI-1 in renal tissue.Results : Compared with the ones in the control group

mice treated with Rofecoxib had lower levels of proteinuria

serum creatinine

serum angiotensin II

urinary thromboxanc B2(P<0.05).The PAI-1 expression and deposition of extracellular matrix in renal tissue significantly decreased(P<0.05).The level of 6-Keton-prostaglandin-F1α was not significantly different(P>0.05).Conclusion: Rofecoxib may decrease proteinuria and ameliorate progressive glomerular sclerosis by inhibiting partly the expression of PAI-1 by decreasing the deposition of extracellular matrix and accelerating its degradation.The specific cyclooxygenase-2 inhibitor has a renoprotective effect on MRL-lpr/lpr mice.