DIFFERENTIAL RESPONSE OF GLUCOSE-UTILIZATION BY 3 RAT MUSCLE TISSUES TO DIETARY FATTY-ACID COMPOSITION

Rats were fed a semisynthetic diet containing 14% of either beef fat, safflower oil, or menhaden oil plus 2% corn oil for 7 weeks, and three tissues, diaphragm, heart, and skeletal muscle, were examined for fat ty acid composition in their phospholipids and triglycerides. In addit ion, the lipid concentrations in these tissues were examined. The in v itro oxidation and incorporation of glucose into lipids of these tissu es were also examined. Skeletal muscle, showed the greatest change in phospholipid composition with diet. All tissues were responsive to cha nges in diet in regards to the triglyceride fraction. Dietary alterati on of tissue phospholipid composition did not alter lipid concentratio n in these tissues. However, in diaphragm tissue, rats fed the beef fa t diet had lower phospholipid and higher triglyceride synthesis compar ed with those fed either menhaden oil or safflower oil. In addition, t riglyceride synthesis was higher in the diaphragm of animals fed the m enhaden oil diet as compared with the safflower oil diet. Therefore, d ietary fatty acid composition may play a role in the triglyceride and phospholipid metabolism of rat diaphragm.