Regulation of Phosphatidylcholine Biosynthesis by the Methylation Pathway in Rat Pituitary Gland

Summary

Rat pituitary extracts catalyze methylation of phosphatidylethanolamine to phosphatidylcholine using S-adenosyl-L-methionine as the methyl donor. In vitro incubation of hemipituitaries with 1 mM 2-methylaminoethanol led to a dose dependent de-crease in phosphatidylethanolamine methyltransferase activity as well as the incorporation of the radioactivity from [³H-methyl]-L-methionine into phosphatidyl-choline. The inhibitory effect of 2-methylaminoethanol was selective for phosphoiipids methylation since protein carboxymethyltransferase and catechol-o-methyltransferase activities were not affected.

Key-Words:

Phosphatidylcholine - Phospholipid methylation - Choline - Pituitary - 2-Methylaminoethanol