Effects of fatty acids on phosphatidylcholine biosynthesis in isolated hamster heart.
The effects of stearic, oleic, and arachidonic acids on phosphatidylcholine biosynthesis in the hamster heart were investigated. When hamster hearts were perfused with labelled choline in the presence of fatty acids, biosynthesis of phosphatidylcholine was stimulated only by stearic acid. Stearic acid was found to accumulate in unesterified (free) form in the hamster heart after perfusion. The stimulation by stearic acid was mediated in vivo by an enhancement of CTP:phosphocholine cytidylyltransferase activity in the microsomal fraction of the hamster heart and the enzyme activity in the cytosolic fraction was not affected. In contrast with the observations in rat hepatocytes, cytidylyltransferase from the hamster heart was not stimulated directly by stearic acid. The selective activation of the microsomal enzyme when the heart was perfused with stearic acid suggests that activation of the enzyme was mediated via the modification of the membrane by stearic acid.
D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D002794:Choline / Q000378:metabolism; D019916:Choline-Phosphate Cytidylyltransferase; D006224:Cricetinae; D005230:Fatty Acids, Nonesterified / Q000494:pharmacology*; D066298:In Vitro Techniques; D007700:Kinetics; D008647:Mesocricetus; D009206:Myocardium / Q000378:metabolism*; D009713:Nucleotidyltransferases / Q000378:metabolism; D019301:Oleic Acid; D009829:Oleic Acids / Q000494:pharmacology; D010713:Phosphatidylcholines / Q000096:biosynthesis*; D013229:Stearic Acids / Q000494:pharmacology
D001095:Arachidonic Acids; D005230:Fatty Acids, Nonesterified; D009829:Oleic Acids; D010713:Phosphatidylcholines; D013229:Stearic Acids; D016718:Arachidonic Acid; D019301:Oleic Acid; C031183:stearic acid; D009713:Nucleotidyltransferases; D019916:Choline-Phosphate Cytidylyltransferase; D002794:Choline