Effects And Mechanisms Of Sal B On Myocardial Ischemia/Reperfusion Injury Of Reactive Oxygen Species

Myocardial ischemia and reperfusion(MI/R) injury has the greatly meaning ofphysiopatholgy in the ischemic heart disease and heart surgery.But its pathogenymechanisms remains incompletely elucidated. At present, reactive oxygen species(ROS)damage and calcium overload are essential mechanisms of MI/R injury, salvianolic acidB,a water-solube composition,was extracted and purified from the rhizome of Salviamiltiorrhiza Bge. Recent investigations indicate that salvianolic acid B are protective onheart, in our lab,we had found that coronary blood flow of isolated rabbit heart can besignificantly increased by salvianolic acid B.In order to further study the antimyocardialischemia/reperfusion effects of salvianolic acid B,we used acute myocardial ischemiamodels,myocardial ischemia and reperfusion model and hypoxia/reoxygenation model ofcardiomyocyte.In the first part of this thesis, the acute myocardial ischemia models of Pit inducedand MI/R model in rats were established to carry on our research. It was found thatsalvianolic acid B could reduce the changes of T waves in rat cardiogram, inhibit theincrease of S-T segment and decrease the release of CK and LDH, AST, XO, MAO andMDA, and that salvianolic acid B could improve activitiy of SOD, CAT and GSH-Px ofhypoxia-reoxygenation injured cardiac myocytes.So salvianolic acid B had protectiveeffects on myocardial ischemia/reperfusion injury mainly by reducing the release of CK,LDH and AST adjusting the balance of Cardiac E and impoving Antioxidation.In the second part,The model of hypoxia-reoxygenation injury in cultured cardiacmyocytes was set up by making the pure cultured neonatal rat cardiac myocytes be lack ofoxygen and then afford oxygen, we studied its protective effects on hypoxia/reoxygen--nation injury in cardiac myocytes, the primary guide lines being observed are: livability,morphologic change and beating rates of cardiac myocytes, activity of LDH, SOD,GSH-Pxand MDA concentration in culture medium. By setting up the apoptosis model of CardiacMyocyte induced by hypoxia/reoxygennation,we observed the antioxidation of salvianolic acid B by cell apoptosis rates. The change f inducible enzyme was analyzed also. Throughthose ways, we try to discuss the mechanisms of salvianolic acid B protecting hypoxia/reo--xygenation injury in cultured cardiac myocytes.The results showed that salvianolic acid B can obviously enhance the livability, active-etiy of SOD and GSH-Px of hypoxia/reoxygenation injured cardiac myocytes. It canameliorate morphologic change of injured cardiac myocytes and reduce their release ofLDH and MDA,and inhibit apoptosis of myocardial cells induced by hypoxia/reoxygena--tion salvianolic acid B have the evident protective effects on hypoxia/reoxygenation injuryin cultured neonatal rat cardiac myocytes.The mechanisms of protective effects of catechinson the cultured neonatal rat myocardial cells injured by hypoxia/reoxygenation are relatedto the antioxidation effects of catechins and inhibitingapoptosisof myocardial cells.