Transfer of methyl groups from N-dimethylnitrosamine to glycerolipids in rat liver.
We have examined the in vivo labeling of lipids after a single intraperitoneal injection of the carcinogen, (C14) dimethylnitrosamine, into rats. Liver was most active in incorporating (C14) methyl groups into lipids (0.91% of the injected dose) and 80% of the activity appeared in sn-3-phosphatidyl-choline. Chromatographic analysis of the products (and derivatives) formed after treatment of the (C14) phosphatidylcholine with phospholipase A2 (EC 3.1.1.4) and phospholipase C (EC 3.1.4.3) demonstrated that 89% of the radioactivity was in the choline moiety. These results indicate the transfer of methyl groups to lipids occurred via the lipid methylation pathway that converts phosphatidylethanolamine to phosphatidylcholine.
D000818:Animals; D002794:Choline / Q000096:biosynthesis; D002855:Chromatography, Thin Layer; D004128:Dimethylnitrosamine / Q000378:metabolism*; D006017:Glycolipids / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D008297:Male; D009602:Nitrosamines / Q000378:metabolism*; D010713:Phosphatidylcholines / Q000096:biosynthesis; D010740:Phospholipases; D051381:Rats
D006017:Glycolipids; D009602:Nitrosamines; D010713:Phosphatidylcholines; D010740:Phospholipases; D004128:Dimethylnitrosamine; D002794:Choline