| First Author | Yu IS | Year | 2004 |
| Journal | Blood | Volume | 104 |
| Issue | 1 | Pages | 135-42 |
| PubMed ID | 15010374 | Mgi Jnum | J:90922 |
| Mgi Id | MGI:3045522 | Doi | 10.1182/blood-2003-10-3661 |
| Citation | Yu IS, et al. (2004) TXAS-deleted mice exhibit normal thrombopoiesis, defective hemostasis, and resistance to arachidonate-induced death. Blood 104(1):135-42 |
| abstractText | Besides its well-recognized role in hemostasis and thrombosis, thromboxane A(2) synthase (TXAS) is proposed to be involved in thrombopoiesis and lymphocyte differentiation. To evaluate its various physiologic roles, we generated TXAS-deleted mice by gene targeting. TXAS(-/-) mice had normal bone marrow megakaryocytes, normal blood platelet counts, and normal CD4 and CD8 lymphocyte counts in thymus and spleen. Platelets from TXAS(-/-) mice failed to aggregate or generate thromboxane B(2) in response to arachidonic acid (AA) but produced increased prostaglandin-E(2) (PGE(2)), PGD(2), and PGF(2 alpha). AA infusion caused a progressive drop of mean arterial pressure (MAP), cardiac arrest, and death in wild-type (WT) mice but did not induce shock in TXAS(-/-) mice or in WT and TXAS(-/-) mice treated with antagonist to the thromboxane-prostanoid (TP) receptor. The TXAS(-/-) mice were able to maintain normal MAP upon AA insult when TP was present but were unable to do so when TP was blocked by an antagonist, suggesting a role of endoperoxide accumulation in influencing MAP. We conclude that TXAS is not essential for thrombopoiesis and lymphocyte differentiation. Its deficiency causes a mild hemostatic defect and protects mice against arachidonate-induced shock and death. The TXAS-deleted mice will be valuable for investigating the roles of arachidonate metabolic shunt in various pathophysiologic processes. |
