Abstract: In this paper,the activity and quantity of tissue-type plasrninogen activator(t-PA) and inhibitor of t-PA (PAI) in plasma of BXSB mice with lupus nephritis were measured by spectrophotometric assay and enzyme linked immunosorbent assay(EI-ISA).The results showed that the amount of urine protein increased significantly.The immunopathologic and histologic changes of BXSB mice with lupus nephritis showed deposition of immune complex and fibrin in glomeruli,thickening of capillary walls and occlusion of capillaries.The activity of t-PA in the plasma of diseased BXSB mice was significantly lower than that in normal mice (P<0.01).These results suggest that thrombosis in SLE is correlated to the low activity of t-PA.

Key words: Lupus erythematosus,systemic, Fibrinolysis