Phosphatides and Cholesterol in the Rat Body: Effects of Growth, Diet and Age

Abstract

Data are presented on the content of phosphatides, free and total cholesterol, and neutral fat in 152 male rats from birth to 3 years of age. The ratio of phosphatides to total cholesterol remained remarkably constant at near 4 (mol ratio of 2) for the first year of life with a variety of diets. Two- and three-year-old rats showed a highly significant decrease in this ratio, corresponding to an increase in total cholesterol of about 10%, with no change in phosphatides. The percentage of free cholesterol decreased steadily throughout life from 90 to 72, diet and senescence having no effect thereon. The pattern of accretion of neutral fat with stock diet was in many respects very different from the common pattern observed for both phosphatides and cholesterol. The substitution of more concentrated, refined or purified diets of varying fat content (2% to approximately 40%) for the crude stock diet led to no change in phosphatides or cholesterol. These same rats showed large increases in neutral fat.