Incorporation of Acetate-2-C14 into Liver and Carcass Lipids and Cholesterol in Biotin-Deficient Rats

Abstract

Biotin-deficient, pair-weighed control, and ad libitum-fed control rats were injected with acetate-2-C¹⁴, one series after 7 and another after 10 weeks on the diet. During a 4-hour period, the biotin-deficient rats were found to excrete the largest proportion of the injected C¹⁴O₂, with the highest specific activity. The pair-weighed controls retained the largest proportion of the injected C¹⁴. The concentration of liver lipids was slightly higher in the pair-weighed rats than in the other two groups. In all cases, the specific activities of the liver lipids and of free and total cholesterol were much the highest in the underfed controls of the pair-weighed groups, as were the percentages of the injected C¹⁴ found in the liver lipids. Carcass fat also had the highest specific activity (counts per minute per milligram) in the pair-weighed groups, but in this case the differences between the pairweighed and deficient groups were small. Liver glycogen, in contrast, showed the greatest activity in the deficient animals. The extent to which the data suggest impairment or alteration in the metabolism of acetate in the biotin-deficient rat is discussed.