De novo fatty acid synthesis in the perfused rat lung. Incorporation of palmitate into phospholipids.
1. The incorporation of exogenously derived [14C]palmitate and endogenously synthesized [3H]palmitate (from 3H2O) was measured in the isolated perfused lung. 2. Over 40% of the fatty acid esterified into lung disaturated phosphatidylcholine was derived from de novo synthesis. 3. A major portion of the palmitate synthesized de novo was incorporated in the 2 position of disaturated phosphatidylcholine. 4. Streptozotocin-induced diabetes and the compound 5-(tetradecyloxy)-2-furoic acid markedly inhibited de novo fatty acid synthesis while the incorporation of exogenously supplied palmitate increased into disaturated phosphatidylcholine, primarily in the 2 position. 5. Treatment with insulin resulted in an increase in [14C]glucose incorporation into lung phospholipid, with the largest increase appearing in the glyceride-glycerol fraction of the phosphatidylcholine species. 6. Insulin neither stimulated de novo fatty acid synthesis nor increased exogenous palmitate incorporation. 7. These data show: (1) that de novo fatty acid synthesis in the perfused rat lung is involved in the remodeling reactions in the synthesis of phosphatidylcholine, and (2) that diabetes affects the relative contribution of de novo synthesized and exogenously supplied palmitate available for the esterification of lung phospholipid.
D000818:Animals; D002250:Carbon Radioisotopes; D005227:Fatty Acids / Q000096:biosynthesis*; D066298:In Vitro Techniques; D008168:Lung / Q000378:metabolism*; D008297:Male; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000378:metabolism*; D010477:Perfusion; D010743:Phospholipids / Q000096:biosynthesis*; D051381:Rats; D011919:Rats, Inbred Strains; D014316:Tritium
D002250:Carbon Radioisotopes; D005227:Fatty Acids; D010169:Palmitic Acids; D010743:Phospholipids; D014316:Tritium; D019308:Palmitic Acid