Effects of Centrophenoxine on Cholinephosphotransferase Activity in Maternal and Fetal Guinea Pig Lung

Abstract

Cholinephosphotransferase activities of guinea pig lung mitochondria and micro-somes are inhibited by centrophenoxine and one of its metabolites, p-chlorophenoxyacetate. 2-Dimethylaminoethanol, the second metabolite of centrophenoxine, has no inhibitory effect on the enzyme activity. The inhibition of enzyme activity by centrophenoxine is noncompetitive. Intravenous injection of centrophenoxine and p-chlorophenoxyacetate to pregnant animals causes inhibition of cholinephosphotransferase activity in adult lung but not in fetal lung. However, direct administration of centrophenoxine to the fetus after laparotomy causes inhibition of both subcellular enzyme activity in fetal lung. It is suggested that the drug injected to the pregnant animals does not reach the fetal lung or is metabolized. Furthermore, while centrophenoxine injection does not change the total phos-phatidylcholine content of adult lung, the acyl group composition of phosphatidylcholine was modulated.