Pyruvate kinase isoenzymes in progressive muscular dystrophy and in acute myocardial infarction

Abstract

The activity of pyruvate kinase was measured in serum from patients with muscular dystrophy, other muscle diseases, acute myocardial infarction and hepatitis. In Duchenne and limb-girdle type dystrophy, activity was elevated 28-fold; elevations were found even when serum aldolase and CPK activities were not elevated. In the late stages of progressive muscular dystrophy, the activity tended to diminish, but remained elevated. In acute myocardial infarction, the activity rose within the first 2 days. The duration and magnitude of this rise (average sevenfold) were similar to those of the SGOT rise. Hepatitis patients who exhibited high levels of SGOT and LDH showed much smaller changes in pyruvate kinase activity. Pyruvate kinase from liver could be differentiated from the isoenzyme present in myocardial and skeletal muscle by appropriate alterations in assay conditions.