Alterações plasmáticas do cobre e do zinco em crianças submetidas a cirurgia cardíaca com circulação extracorpórea

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

The cardiac surgery, comprising extracorporeal circulation, is known to trigger oxidative stress due to the formation of reactive oxygen species and free radicals during the periods of ischemia and reperfusion. They are hazardous to the heart cell components and regarded as responsible for the myocardial stunned. These processes are intricately associated with the metabolism of the most important trace elements, copper and zinc. The former, in the form of weakly bonded or free ions, can easily provoke a massive sprout of free radicals, thus contributing to lipid peroxodation, DNA damage and other undesirable consequences. The latter acts as natural antioxidant, substitutes for copper in the active catalyst centers of major enzymes and carriers, and plays a significant role in the processes of cell and tissue proliferation. The purpose of the present work was to evaluate the alterations observed in the trace elements levels in children, which undergo cardiac surgery with cardiopulmonary bypass. Twenty one children of the age between 2 and 14 years took part in the study. The following blood samples were collected for copper, ceruloplasmin and zinc analysis: from venous line before the operation; from right atrium; from oxygenator of the extracorporeal circuit, on 5th and 10th minutes of bypass; from coronary sinus and oxygenator, simultaneously, on 3d minutes after the removal of aortic cross-clamp; at the end of the procedure and 24 hours after, that is in post-operative period. The main haemodynamic parameters, such as blood pressure, heart rate and ECG showed neither unexpected alterations, nor correlations with copper and zinc levels. Plasma concentration of copper before the operation in the group studied was higher than average in the children population. Its decrease was deeper than predicted by haemodilution and the values returned to normal and at the end of the surgical intervention. The changes in ceruloplasmin concentrations were similar to those of total copper, but showed lesser deviations. Its values returned to normal after 24 hours. Zinc concentrations before the operation in the group studied were lower than average for normal children, and there were no significant changes during the bypass, confirming that this element was not involved in the metabolic alterations, but corroborate the key role of copper in these processes. The variations in copper and zinc concentrations were not correlated. The study concluded that the changes of copper and zinc showed less oxidative stress and consequently less damage cell.

ASSUNTO(S)

zinco copper cardiopulmonary bypass cobre cardiologia pediátrica zinc circulação extracorpórea ciencias da saude pediatric cardiology

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