The metabolic effect of carbon monoxide on the heart.

The acute effects of carbon monoxide (CO) on cardiac metabolism at the mitochondrial level were investigated. Rats were exposed to 4% CO for 4 minutes in a closed chamber. Immediately after exposure, hearts were removed and frozen with a precooled clamp. Blood from the thoracic cavity was sampled for analysis. Gas analysis of arterial blood taken from the abdominal aorta demonstrated severe hypoxia with oxygen partial pressure less than 20 mmHg, metabolic acidosis and reduced pH value. There were no significant changes in the plasma level of glucose and non esterified fatty acids (NEFA). In the myocardium, ATP levels decreased significantly, and concomitantly, a significant increase in the plasma uric acid level was observed. Although no significant change was observed in short chain acyl carnitine, free carnitine levels decreased to one fourth of the control value. Long chain acylcarnitine increased 11-fold. Coenzyme Q9 (CoQ9) level decreased significantly, but there was no significant change in Coenzyme Q10 (CoQ10).