21. A heme group coordinated to a cysteine residue from the enzyme, thromboxane synthase, is involved in the mechanism. 22. "' Ozagrel "'( INN ) is an antiplatelet agent working as a thromboxane A2 synthesis inhibitor. 23. Unlike thromboxane synthase inhibitors such as ozagrel, seratrodast does not affect thrombus formation, time to occlusion and bleeding time. 24. These " Sticky platelets " secrete several chemicals, including thromboxane A2 that stimulate vasoconstriction, reducing blood flow at the site. 25. The human thromboxane A ( TXA ) synthase is a 60 kDa protein with 533 amino acids and a heme prosthetic group. 26. It also sometimes is used to reduce platelet aggregation by inhibiting degranulation of platelets which reduces the release of ADP and thromboxane . 27. Aspirin blocks an enzyme, cyclo-oxygenase, that is involved in producing thromboxane , a substance that induces platelets to clump. 28. Aspirin works by blocking the formation of thromboxane A2, a chemical in the body that makes platelets sticky and promotes blood clotting. 29. However the serotonin and the thromboxane A2 cause more contraction of the smooth muscle cells and as a result contractions outweigh the relaxations. 30. In catalyzing the synthesis of thromboxanes, TXA synthase is involved in a flux pathway that can modulate the amount of thromboxane produced.
