Comparative effects of chronic ethanol and acetaldehyde exposure on myocardial function in rats.

This study was conducted to compare separately the chronic effects of high blood levels of ethanol and acetaldehyde on the metabolism of the heart. Levels of ethanol and acetaldehyde were altered by administration of either 4-methylpyrazole (4-MP), a potent alcohol dehydrogenase inhibitor, or pargyline (PAR), a monoamine oxidase inhibitor that markedly increases acetaldehyde levels in the blood following ethanol administration. Measurements were made in rats consuming ethanol for three to four weeks. Mitochondrial respiration, in vitro contractility of glycerinated heart muscle fibers, and myocardial protein synthesis were determined. As compared to animals receiving only ethanol, administration of either-4-methyl-pyrazole or pargyline plus ethanol resulted in more severe damage to mitochondrial respiration and myocardial protein synthesis. The data illustrate that both acetaldehyde and ethanol in high concentrations can cause severe damage to myocardial metabolism.