title: Thyroxine stimulates the acylation of lysophosphatidylethanolamine in rat heart.
abstract: The acylation of cardiac lysophosphatidylethanolamine (LPE) was examined in rats treated with thyroid hormone. Rats were treated for five consecutive days with thyroxine (250 microg/kg) and controls were treated with saline. On the sixth day after an overnight fast, the hearts were removed and perfused in the Langendorff mode with 0.1 mM [1-14C]oleic acid. Radioactivity incorporated into phosphatidylethanolamine (PE) was increased 1.5-fold (P < 0.025) compared to controls. Radioactivity incorporated into phosphatidylcholine was not effected. The pool size of phosphatidylethanolamine and de novo biosynthesis of this phospholipid from [3H(G)]serine or [1,2-14C]ethanolamine were unaltered by thyroxine treatment. Treatment of rats with thyroxine resulted in a 1.5-fold (P < 0.025) increase in the relative percent of oleic acid in cardiac phosphatidylethanolamine. Thyroxine treatment resulted in a 1.8-fold (P < 0.025) increase in cardiac microsomal acyl-coenzyme A:1-acyl glycerophosphorylethanolamine acyltransferase activity compared to controls whereas, phospholipase A, acyl-coenzyme A hydrolase and fatty acyl-coenzyme A synthase activities were unaltered. The results demonstrate that the reacylation of cardiac LPE is regulated by thyroid hormone.
authors.affiliation: Departments of Biochemistry and Molecular Biology and Pharmacology and Therapeutics, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: V W
authors.initials: VW
authors.lastname: Dolinsky
authors.forename: G M
authors.initials: GM
authors.lastname: Hatch
mesh_terms: D008243:1-Acylglycerophosphocholine O-Acyltransferase / Q000378:metabolism; D000215:Acylation; D000217:Acyltransferases / Q000378:metabolism; D000818:Animals; D006321:Heart / Q000187:drug effects*; D066298:In Vitro Techniques; D008246:Lysophospholipids / Q000378:metabolism*; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D019301:Oleic Acid / Q000378:metabolism; D010477:Perfusion; D010713:Phosphatidylcholines / Q000378:metabolism; D010714:Phosphatidylethanolamines / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013974:Thyroxine / Q000494:pharmacology*
chemical_list: D008246:Lysophospholipids; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; C008301:lysophosphatidylethanolamine; D019301:Oleic Acid; D000217:Acyltransferases; C042139:phosphatidylethanolamine N-acyltransferase; D008243:1-Acylglycerophosphocholine O-Acyltransferase; D013974:Thyroxine