Cholesterol absorption in baboons.

We estimated the effects of age, sex, saturated and polyunsaturated dietary fat, and two levels of dietary cholesterol intake on cholesterol absorption in juvenile baboons between 15 and 51 months of age. We compared the reproducibility of methods of measuring cholesterol absorption within animals, and also compared estimates of percentage cholesterol absorption by three different methods. Cholesterol absorption was significantly greater in all diet groups at 27 and 39 months of age than it was at 15 or 51 months (P < 0.001). Cholesterol absorption (%) was significantly greater in animals fed low cholesterol diets than it was in animals fed high cholesterol diets. However, cholesterol absorption was not affected by type of fat (saturated or unsaturated) in the diet or by sex. The range of reproducibility (within-animal standard deviation) of percentage cholesterol absorption for different diet groups was 3.35 to 3.90% for the Borgström method (1969. J. Lipid Res. 10: 331--337), 4.67 to 7.30% for the Sodhi method (1971. Proc. Soc. Exp. Biol. Med. 137: 277-279), and 3.69 to 7.15% by a combined isotopic chromatographic method (Method I). Percentage absorption measured by either the Sodhi method or Method I was significantly greater than that measured by the Borgström method.