The molecular species of mucosal phosphatidyl cholines from the small intestine of normal and essential fatty acid-deficient rats

Abstract

1. 1. Phosphatidyl cholines from the intestinal mucosa of rats maintained on semisynthetic diets containing either 10% corn oil or 10% hydrogenated coconut oil were subjected to hydrolysis with phospholipase C (EC 3.1.4.3) and the resulting diglycerides were fractionated on thin layers of silica gel impregnated with AgNO 3. The individual diglyceride fractions were then hydrolyzed with pancreatic lipase (EC 3.1.1.3). The fatty acid compositions of the diglycerides and the 2-monoglycerides were determined by gas-liquid chromatography in order to characterise the molecular species of phosphatidyl cholines present in the mucosal lipids. 2. 2. The most abundant species of mucosal phosphatidyl cholines in rats fed corn oil was 16:0–20:4 which accounted for almost 20% of the total phosphatide. This was closely followed by the stearic acid anolog, 18:0–20:4. Substantial amounts of 16:0–18:2, 18:0–18:2 and 16:0–18:1 were also present. 3. 3. A dietary deficiency of essential fatty acids resulted in the partial replacement of arachidonic acid-containing species by 16:0–20:3 and 18:0–20:3, and of linoleic acid-containing species by 16:0–18:1 and 18:0–18:1. Substantial amounts of 16:0–20:4 and 18:0–20:4 were present, however. The most abundant species in this group was 16:0–18:1. A lower level of palmitic acid in the mucosal phosphatidyl choline from the deficient rats was reflected in a decrease in the species containing this acid relative to corresponding species containing stearic acid.