The effects of imipramine on the methylation of phosphatidylethanolamine (PE) in the cortical membranes of Wistar rats.

This study investigates the effect of imipramine (IMI) on the methylation of phosphatidylethanolamine (PE) in crude cortical membranes of rat brain in vitro and ex vivo. It was found that IMI enhanced the formation of phosphatidyl-N-monomethylethanolamine (PME) and phosphatidyl-N,N-dimethylethanolamine (PDE) and inhibited the formation of phosphatidylcholine (PC) in the cortical membranes of rats in vitro. The same effect i.e. increased incorporation of methyl groups in PE and PME and decreased formation of PC was found in the cortical membrane of rats killed 1 hr after intraperitoneal administration of IMI at a single dose of 10 mg/kg. Chronic treatment of rats with IMI for 14 days with a daily dose of 10 mg/kg i.p. led to further inhibition of PC formation but did not affect the formation of PME and PDE and abolished the stimulating effect of IMI on the formation of PME and PDE in vitro.