Experimental Study of Fibrinolytic Factors and Its Inhibitors in Rabbits’ Tissues Extract.

Objective: To study the expression character of fibrinolytic factors and its inhibitors in rabbits’ tissues extract. Methods: Tissue plasminogen activator ( tPA ), Plasminogen activator inhibitor-1 ( PAI-1 ), Plasminogen ( Plg ), Plasmin ( Pl ) and α2 Plasmin inhibitor ( α2PI ) were measured by colorimetric assay. Results: The tissues extract in renal, small intestine, lung, brain and spleen showed strong fibrinolytic function, and expressed markedly high activity levels of tPA, Plg and Pl. But striped muscle, tongue and stomach expressed markedly high activity levels of PAI-1 and α2PI, and showed low fibrinolytic character. There were linear correlation between levels of tPA and PAI-1 ( r=−0.8076, P<0.01 ), Pl and αPI ( r=−0.3278, P<0.05 ), Plg and Pl ( r=0.6811, P<0.01 ) in tissues extract fibrinolytic targets. In relative tissues, renal cortex and renal marrow were significantly high level of tPA and low level of PAI-1, but levels of Plg and Pl in cortex renalis were higher than in renal marrow, the α 2PI level in renal marrow were higher than in renal cortex ( P<0.05~0.01 ). The levels of tPA, Plg and Pl in small intestine were higher than tin large intestine ( P<0.05~0.01 ), but the levels of PAI-1 and α 2PI in small intestine were markedly lower than in large intestine ( P<0.01 ). These indicated that fibrinolytic function in small intestine was stronger than in large intestine. Although the fibrinolytic function in muscle tissue was low, but the levels of tPA, Plg, and Pl in cardiac muscle were obviously higher than in striped muscles, and the levels of PAI-1 and α 2PI were obviously lower than in striped muscle ( P<0.05~0.01 ). These indicated that the fibrinolytic function in cardiac muscle were stronger than in the striped muscle. Conclusion: The fibrinolytic character existed significant difference in tissues, it has profound significance in the function of heamostasis and thrombosis and physiologic function in tissues.