EFFECT OF SPHINGOMYELIN AND ANTIOXIDANTS ON THE IN-VITRO AND IN-VIVO DNA METHYLATION

Sphingomyelin and product of its enzymatic hydrolysis, sphingosine, in fluence on the degree of DNA methylation by EcoRII cytosine DNA-methyl transferase. Sphingomyelin activates (up to 30%), whereas sphingosine inhibits this in vitro DNA methylation. A single intraperitoneal injec tion of the synthetic antioxidant, butylated hydroxytoluene (BHT, 30 m g/kg body weight) results in DNA hypermethylation as well as increase in sphingomyelin content in rat liver nuclei and RNA-polymerase activi ty. Thus, phospholipids may control DNA methylation in cell, and by th is way they seem to modulate replication and transcription.