The central theme of my research is to understand the reaction mechanism of several crucial heme-containing proteins that are involved in regulatory functions and the pathological processes of the cardiovascular system. Prostaglandins and nitric oxide (NO) are two important mediators in hemostasis. For example, prostacyclin and NO released by endothelial cells are strong vasodilators and potent inhibitors of platelet aggregation, whereas thromboxane and prostaglandin G2/H2 released by platelets are potent agonists of platelet aggregation and vasoconstriction. All these compounds are short-lived autocoids. A balanced production and timely release of these potent hormones are crucial in maintaining a normal vascular tone and an imbalanced synthesis of these mediators usually leads to pathological conditions.