title: Lack of modulation by dietary unsaturated fats on sympathetic neurotransmission in rat hearts.
abstract: We examined the effect of dietary polyunsaturated fatty acids (PUFA) on cardiac sympathetic neurotransmission. Rats were fed semisynthetic diets (18.5% fat wt/wt) high in saturated fatty acids (control diet), high in n-6 PUFA (corn oil), or enriched with n-3 PUFA (Maxepa). A perfused innervated heart model was used to examine different aspects of sympathetic neurotransmission 10 wk after the feeding. Dietary PUFA increased the content of n-6 or n-3 PUFA in myocardial phospholipids compared with animals fed control diets. Myocardial norepinephrine content, sympathetic nerve stimulation-induced norepinephrine release, neural reuptake, presynaptic alpha-adrenergic inhibition of norepinephrine release, and postsynaptic inotropic response (+/- dP/dt) to sympathetic nerve stimulation or to a beta-agonist were essentially not influenced by dietary PUFA. Neural norepinephrine release during prolonged ischemia (60 min) was also similar in hearts from rats fed n-6 PUFA and control diets. Thus a modification of sympathetic neurotransmission was not achieved by feeding PUFA-enriched diets for 10 wk.
authors.affiliation: Department of Medicine (Royal Infirmary of Edinburgh), University of Edinburgh, United Kingdom.
authors.forename: X J
authors.initials: XJ
authors.lastname: Du
authors.forename: A M
authors.initials: AM
authors.lastname: Dart
authors.forename: R A
authors.initials: RA
authors.lastname: Riemersma
mesh_terms: D000818:Animals; D004041:Dietary Fats / Q000494:pharmacology*; D004558:Electric Stimulation; D005224:Fats, Unsaturated / Q000494:pharmacology*; D005227:Fatty Acids / Q000378:metabolism; D043371:Fatty Acids, Omega-6; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology; D006329:Heart Conduction System / Q000187:drug effects*; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D017202:Myocardial Ischemia / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism; D051381:Rats; D011917:Rats, Inbred Lew; D013564:Sympathetic Nervous System / Q000187:drug effects* / Q000378:metabolism; D009435:Synaptic Transmission / Q000187:drug effects*
chemical_list: D004041:Dietary Fats; D005224:Fats, Unsaturated; D005227:Fatty Acids; D043371:Fatty Acids, Omega-6; D005231:Fatty Acids, Unsaturated; D007545:Isoproterenol; D009638:Norepinephrine