Effect of antecedent diet and of cortisone treatment on cholesterol-4-C¹⁴ metabolism in rabbits

¹ Dorn Laboratory for Medical Research, Bradford Hospital, Bradford, Pennsylvania

Metabolic behavior of a test meal containing cholesterol-4-C¹⁴ (10 µc C¹⁴; 1 gm cholesterol) was observed through 2 days in rabbits previously fed for 35 days a normal diet (A), and high-cholesterol diet alone (B) and concurrent cortisone treatment (C). In the early postprandial period the relative incorporation of cholesterol-4-C¹⁴ in the plasma-free and ester cholesterol differed markedly in the three groups. In group C the activity in the plasma cholesterol fractions increased precipitously and maxima specific activities were reached with the 24-hour blood sample while in groups A and B activity in the plasma increased much slower. C¹⁴-cholesterol was not incorporated in aorta ester cholesterol of groups A and C 2 days following the labeled cholesterol meal while in aortas of group B a definite amount of ester cholesterol-4-C¹⁴ was found. Free and ester cholesterol-C¹⁴ quantities in the liver, the plasma and the ileum were greater in group B than that present in respective tissues of group A. On the other hand, larger quantities of liver ester cholesterol-C¹⁴ and plasma free cholesterol-C¹⁴ were present in group C than in B. The results indicated that metabolic handling of a cholesterol meal was influenced by type of previous diet regimen and that cortisone treatment modified dietary cholesterol behavior in the cholesterol-fed rabbit.