Membranes, Methylation and Lithium Responsive Psychoses

Data are presented showing that the erythrocyte ghost membranes of lithium-responsive and non-responsive schizophrenic-like patients are different from control membranes. In both groups of patients there was a significant decrement of phosphatidylcholine (PC) which was largely compenstated for by an increase in sphingomyelin. The decrement in PC may in part be associated with a decrease in phospholipid methylation which converts phosphatidylethanolmine (PE) to PC. Interestingly, in the lithium-responsive but not the non-responsive patients, lithium stimulates methylation activity. This stimulation may affect a variety of membrane functions, e.g. adenyl cyclase activity, which would be involved in lithium's therapeutic actions.