The influence of dietary inositol on glyceride composition and synthesis in livers of rats fed different fats.

The effect of inositol supplementation on the composition and biosynthesis of glycerides in the livers of rats fed diets containing fats with differing fatty acid composition was investigated. The dietary fats employed in these studies included corn oil, Tower rapeseed oil (RSO), partially hydrogenated soybean oil (SBO), and tallow. No significant influence of inositol on hepatic triglyceride levels was found in animals fed corn oil and SBO whereas inositol deficiency caused a two-and four-fold elevation in triglyceride concentrations in the RSO and tallow groups, respectively. The level of total fatty acids in phospholipid (mg/g liver) was slightly decreased in all fat groups and included a notable decrease in the concentration of monoenoic (18:1) and dienoic (18:2) acids in the RSO and tallow groups. Dietary inositol had a minor effect on the weight % of individual fatty acids in hepatic triglycerides. Inositol-deficient animals showed an increased rate of glyceride synthesis from glycerol-3-phosphate (glycerol-3-P) regardless of the type of fat that was fed. The results indicate that triglyceride accumulation in liver under conditions of inositol deficiency is not only produced with highly saturated fats since the most unsaturated of all the fats tested, Tower RSO, also gave the syndrome. The results further suggested that the accumulation of hepatic lipid due to the feeding of inositol-deficient diets likely arises from their effect on specific metabolic site(s) other than the conversion of glycerol-3-P into lipid.