INFLUENCE OF PYRUVATE, THREONINE AND PHOSPHOETHANOLAMINE ON ACTIVITIES OF SOME ACETALDEHYDE-PRODUCING ENZYMES

Threonine (50 mg/100 g, i.p.) leads to increased hepatic threonine ald olase activity in rats, although endogenous ethanol concentrations rem ain stable. After pyruvate administration (50 mg/100 g, i.p.), endogen ous blood ethanol levels are raised within 30 min, but return to norma l at 60 min. The activity of threonine aldolase is decreased in the li ver, whereas phosphoethanolamine lyase and pyruvate dehydrogenase acti vities remain unchanged. Phosphoethanolamine administration (23 mg/100 g, i.p.) did not change the endogenous ethanol concentration or pyruv ate dehydrogenase, threonine aldolase and phosphoethanolamine lyase ac tivities. Pyruvate appears to be a better precursor of acetaldehyde th an threonine or phosphoethanolamine.