Associations Of Polymorphisms In Angiotensin Converting Enzyme Genes And Perioperative Myocardial Protection During Cardiopulmonary Bypass

Objective: To observe the expression of angiotensin converting enzyme (ACE),angiotensin II (AngII),cardiac troponin (cTnI), creatine kinase isozymes (CK-MB)and muscle red protein(Myo) after cardiopulmonary bypass (CPB). At the same timeto investigate the associations of Polymorphisms in Angiotensin converting enzymeGenes and myocardial injury.Methods： Sixty-three patients who suffered from rheumatic mitral stenosisscheduled for mitral valve replacement with CPB,were randomly divided into threegroups according Polymorphisms in Angiotensin converting enzyme Genes: type II,type ID, type DD (each=21).Blood samples were withdrawn from artery beforeoperation(T1), at the beginning of CPB(T2),30min after CPB(T3),(T4)at the end ofCPB(T5),2h after CPB(T6),6h after CPB(T7) to mearsure the expression of ACE,AngII, cTnI, CK-MB, Myo, cardium samples were collected for hematoxylin andeosin (HE) staining.Results: The level of ACE during and after CPB were significantly higher thanthose before CPB(P<0.05). As extension of CPB time,the expression of ACE isincreasing. The level of cTnI,CK-MB, Myo after CPB were significantly higher thanthose before CPB(P<0.05).The level of cTnI,CK-MB and Myo are highest at T7, T6and T5and T7, respectively.The level of ACE, AngII, cTnI in patients with DDgenotype was significantly higher than the ID and II genotype (p <0.05).Besides, thelevel of ACE, AngII in patients with ID genotype was significantly higher than the II(p <0.05).Conclusion：(1) CPB perioperative midterm ACE and cTnI、Myo、CK-MB tohave certain correlation；(2) ACE DD genotype belongs to susceptibility genesof the CPB perioperative myocardial injury.