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2.
Arch. cardiol. Méx ; Arch. cardiol. Méx;79(2): 157-164, abr.-jun. 2009.
Artigo em Espanhol | LILACS | ID: lil-565716
3.
Cardiovasc Res ; 73(4): 710-9, 2007 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-17224138

RESUMO

OBJECTIVE: In animal models, formation of oxidants during postischemic reperfusion may exert deleterious effects ("oxidative stress"). Cardioplegic arrest/reperfusion during cardiac surgery might similarly induce oxidative stress. However, the phenomenon has not been precisely characterized in patients, and therefore the role of antioxidant therapy at cardiac surgery is a matter of debate. Thus, we wanted to ascertain whether the relationship between oxidant formation and development of myocardial injury also translates to the situation of patients subjected to cardioplegic arrest. METHODS: In 24 patients undergoing coronary artery bypass, trans-cardiac blood samples and myocardial biopsies were taken before cardioplegic arrest and again following reperfusion. RESULTS: Cardiac glutathione release (marker of oxidant production) was negligible at baseline (0.02+/-0.04 micromol/L), but it increased 15 min into reperfusion (1.10+/-0.40 micromol/L; p<0.05); concomitantly, myocardial concentration of the antioxidant ubiquinol decreased from 144.5+/-52.0 to 97.6+/-82.0 nmol/g (p<0.05). Although these changes document cardiac exposure to oxidants, they were not accompanied by evidence of injury. Neither coronary sinus blood nor cardiac biopsies showed increased lipid peroxide concentrations. Furthermore, electron microscopy showed no major ultrastructural alterations. Finally, full recovery of left ventricular systolic and diastolic function was observed. CONCLUSIONS: Careful investigation reveals that while oxidant production does occur during cardiac surgery in patients with chronic ischemic heart disease, cardiac oxidative stress may not progress through membrane damage and irreversible injury.


Assuntos
Ponte Cardiopulmonar/efeitos adversos , Ponte de Artéria Coronária/efeitos adversos , Doença da Artéria Coronariana/cirurgia , Miocárdio/metabolismo , Idoso , Análise de Variância , Biomarcadores/sangue , Doença da Artéria Coronariana/metabolismo , Doença da Artéria Coronariana/patologia , Feminino , Glutationa/sangue , Humanos , Período Intraoperatório , Peroxidação de Lipídeos , Masculino , Microscopia Eletrônica , Pessoa de Meia-Idade , Mitocôndrias Cardíacas/ultraestrutura , Isquemia Miocárdica/metabolismo , Isquemia Miocárdica/patologia , Reperfusão Miocárdica , Miocárdio/química , Miocárdio/ultraestrutura , Oxidantes , Estresse Oxidativo , Período Pós-Operatório , Substâncias Reativas com Ácido Tiobarbitúrico/análise
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