Summary: The effect of a chronic intake of dietary alcohol upon myocardial enzymes was studied in rats. Alcohol, comprising more than 40% of the dietary calorie content, was administered to rats for 6 or 12 weeks. To assess the metabolic changes in the myocardium, the following enzymes were measured: lactate dehydrogenase (LDH), malate dehydrogenase (MDH), aldolase (ALD), isocitrate dehydrogenase (ICDH), creatine kinase (CK) and glutamate-pyruvate transaminase (GPT).The activity of CK was decreased (4.79±0.99 U·mg-1 protein) after 6 weeks on alcohol and was significantly different from that of the controls (5.98±1.44 U·mg-1 protein). After 12 weeks the CK activity of alcoholic rats had recovered to 5.99±1.08 U·mg protein-1 and approached the value found in the normal myocardium. A pronounced decrease was found in the activity of MDH: 8.26±0.69 U·mg protein-1 in the controls, and 6.78±1.07 U·mg protein-1 and 5.79±0.85 U·mg protein-1 in the alcoholic rats after 6 and 12 weeks, respectively. The LDH activity decreased to a lesser extent, but significantly: 2.45±0.18 U·mg protein-1 in the controls, and 2.11±0.07 U·mg protein-1 and 2.06±0.29 U·mg protein-1 after 6 and 12 weeks on test. Only slight, not significant, changes were observed for the other enzymes investigated (ICDH, ALD, GPT). The distribution of LDH and MDH isoenzymes, as well as changes in the MDH/LDH and MDH/ALD ratios, suggests a slowing-down of the oxidative processes and a relative preponderance of glycolysis in the alcoholic rats. The possible pathogenesis of the enzyme activity changes brought about by chronic alcohol ingestion is discussed.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine
- Physiology (medical)