Relationship between fatty acids and lipid peroxidation in lungs of neonates.

Triglycerides from the lungs of neonatal rats and mice were found to contain large amounts of the polyunsaturated fatty acids, arachidonate (20:4) and docosahexaeonoate (22:6). These fatty acids were diminished or absent in the triglycerides from the lungs of adult rats and mice and both neonatal and adult guinea pigs. No age-related changes were observed in the fatty acid composition of lung phospholipids in any of these species. The presence of arachidonic acid and docosahexaenoic acid in lung triglycerides correlated with the ability of these lungs to peroxidize lipids in vitro in all species. Depletion of lung triglycerides in neonatal rats by fasting abolished this lipid peroxidizing activity.