ATRIAL-NATRIURETIC-PEPTIDE INHIBITS THE EXPRESSION OF TISSUE FACTOR AND PLASMINOGEN-ACTIVATOR INHIBITOR-1 INDUCED BY ANGIOTENSIN-II IN CULTURED RAT AORTIC ENDOTHELIAL-CELLS

The pharmacological characteristics of atrial natriuretic peptide (ANP ), such as natriuresis, vasodilation, or suppression of smooth muscle cell proliferation, are well investigated. However, this is the first study to report its role on blood coagulation and fibrinolysis mediate d by vascular endothelial cells. In this study, the effects of ANP on the enhanced expression of tissue factor (TF) and plasminogen activato r inhibitor 1 (PAI-1) by angiotensin II (Ang II) in cultured rat aorti c endothelial cells (RAECs) were examined. The expressions of TF and P AI-1 mRNA were detected by northern blotting methods. The activities o f TF on the surface of RAECs and PAI-1 in the culture media were measu red by chromogenic assay. ANP suppressed mRNA expressions of TF and PA I-1 induced by Ang II in a concentration-dependent manner. This suppre ssion was accompanied by the decreased activities of TF and PAI-1.