title: Influence of dietary linoleic acid on cardiac function and prostaglandin release and on the effects of isoprenaline in the isolated rat heart.
abstract: We studied the effects of dietary linoleate on cardiac function and on the effectiveness of isoprenaline in isolated rat heart preparations. Male Wistar rats were fed either a diet rich in linoleic acid (LA) (25% of digestible energy as sunflower oil, 5% lard) or an LA-deficient diet (30% hydrogenated palm kernel oil). Control rats received a standard lab chow. Under certain experimental conditions the LA-rich diet resulted in increased contractile force, coronary flow rate, and prostaglandin (PG) release (PG-like substances and PGI2) and in a reduction in heart rate. These effects were modified by the duration of the feeding period and/or the age of the animals. In isolated perfused hearts of rats fed on a diet rich in LA for a 10-week period the inotropic effects of isoprenaline were diminished, whereas the isoprenaline-induced increase in coronary flow rate was augmented. The PG-releasing effect of isoprenaline was antagonized by the LA-rich diet. Preliminary in vivo investigations support these in vitro results. The mechanisms by which dietary LA influences cardiac function and the effectiveness of isoprenaline remain unclear.
mesh_terms: D000821:Animal Feed; D000818:Animals; D001783:Blood Flow Velocity; D001794:Blood Pressure / Q000187:drug effects; D004041:Dietary Fats / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects / Q000502:physiology*; D006334:Heart Function Tests; D006339:Heart Rate / Q000187:drug effects; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology*; D008041:Linoleic Acids / Q000494:pharmacology*; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D009206:Myocardium / Q000378:metabolism*; D010477:Perfusion; D011453:Prostaglandins / Q000096:biosynthesis*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D004041:Dietary Fats; D008041:Linoleic Acids; D011453:Prostaglandins; D007545:Isoproterenol