Reversible alterations in fatty acid composition of heart muscle membrane phospholipids induced by epinephrine in rats fed different fats.

The effect of epinephrine on the fatty acid composition of heart muscle phospholipids was examined in rats fed diets containing 10% by weight of butter, corn oil, or cod liver oil. Repeated administration of epinephrine caused elevation of docosahexaenoic acid in phosphatidylcholine and phosphatidylethanolamine and a corresponding decrease in linoleic acid content. Arachidonic acid was increased in phosphatidylcholine and decreased or unaltered in phosphatidylethanolamine. These alterations were qualitatively similar despite different initial levels of fatty acids due to different dietary fats. The initial level of arachidonic acid in phosphatidylcholine and phosphatidylethanolamine was more than 50% lower in the rats fed cod liver oil than in rats fed butter and was partially replaced by the (n-3) fatty acids docosahexaenoic and eicosapentaenoic acid. Dietary corn oil produced less changes in fatty acid composition than cod liver oil compared to the reference diet, 10% butter. The results demonstrate that repeated administration of epinephrine caused significant alterations in fatty acid composition of major phospholipids in heart muscle of rats fed diets enriched with either butter, corn oil, or cod liver oil.