Inhibition of ornithine decarboxylase in the stomach and small intestine of rat by a single dose of ethanol

Abstract

The activity of ornithine decarboxylase (EC 4.1.1.7) in the wall of proximal small intestine (duodenum and 10 cm of proximal jejunum) and in the wall of stomach was significantly reduced 4 h after intragastric administration of 40% ethanol (2g/kg body wt.). Lower concentrations (10% and 20%) also diminished the enzyme activity in the stomach and small intestine. The time dependence of the inhibition of ornithine decarboxylase (the inhibition was greater 4 h after the intubation than after 2 h) suggested that the decrease in the activity seen after ethanol treatment was mediated, at least in part, via protein synthesis. It was shown that the inhibition of ornithine decarboxylase was most likely caused by the ethanol itself because the inhibition was still apparent after treatment with 4-methylpyrazole which so retarded acetaldehyde formation that none was detectable in the wall of the stomach and in the blood and very little in the wall of small intestine.