Turnover of bile acids in the hypercholesterolemic rat as influenced by saturation of dietary fat

Injections of 24-¹⁴C] chenodeoxycholate and³H-cholate were made by heart puncture into 300 g male rats that bore T-cannulas in their bile ducts. The animals had been raised on diet A, containing glucose, cholesterol and cholate, or diet B, containing sucrose and cholesterol; each of the diets contained 5% safflower oil or 5% beef tallow as variables. From analysis of bile samples collected from the T at intervals over a 5 day period, it was observed that the safflower oil group fed diet B had a 17% shorter cholate half-life, a 29% larger cholate pool size and 52% higher rate of cholate synthesis than those fed beef tallow in the same diet. The safflower group fed diet A also had a larger cholate pool size, but synthesis and half-life were obscured by cholate feeding. Chenodeoxycholate turnover data were not obtainable because the decay curves were bimodal for all treatments and hence did not conform to a simple pool model. It is concluded that dietary safflower oil causes more rapid formation of cholate than does dietary beef tallow in the cholesterol-fed rat. Journal Paper No. 4952 AES, Purdue University.