Influence of Glyceride Structure and Fatty Acid Composition on Fat Nutrition.

Abstract

Abstract : We have shown that feeding palmitoyl glycerol to weanling mice results in death within a few days or poor growth in the survivors. Adding small amounts of unsaturated fats will prevent the toxicity. Free palmitic acid is not as toxic as palmitoyl glycerol, and the position of the palmitate on the glycerol does not affect its toxicity. Although linoleic and gamma-linolenic afford the most protection, oleic acid is also protective. Changing the chain length, position of the double bond or its configuration greatly decreases or eliminates the protective effects of unsaturated fat. Animals that die show a severe inflammatory reaction in their lungs that we have termed interstitial pneumonitis. The interstitium of the lungs is so filled with macrophages and leukocytes that severe alveolar stasis and collapse occurs, resulting in death, probably from congestive heart failure. In collaboration with Dr. Ralph Snyderman of Duke University, we have shown that extracts of the affected lung contain a compound(s) that is chemotactic toward murine macrophages. Although the precise mechanism behind the toxicity is unknown, present evidence points to a defect in the metabolism of arachidonic acid. (Author)