S-adenosyl-L-methionine modulates phosphatidylethanolamine methyltransferase response to isoproterenol in brain.

The effect of l-isoproterenol on S-adenosyl-L-methionine (Adomet)-mediated phospholipid methylation in rat brain cortex was examined. Under conditions which favor the activity of methyltransferase I (i.e. low Adomet), formation of phosphatidyl-N-methylethanolamine was inhibited by l-isoproterenol. On the other hand, methyltransferase II activity (i.e. high Adomet) was stimulated by l-isoproterenol. The results suggest that Adomet may play a regulatory role in the response of phospholipid methyltransferases to catecholamines in brain.