Influence of chenodeoxycholic acid on the kinetics of endogenous triglyceride transport in man

Plasma lipids and triglycerides kinetics were studied in ten subjects before and after 6-8 weeks treatment with 1 g/day chenodeoxycholic acid for radiolucent gallstones. Plasma triglyceride concentration fell by 20% and phospholipid concentration rose by 5% on average; there was no change in cholesterol or free fatty acids. Body weight remained constant. Triglyceride kinetics, studied by a precursor-labelling technique, revealed a reduction both of triglyceride plasma pool and turnover rate, accompanied by a decline of more than 35% both of plasma triglyceride precursor pool and of incorporation of plasma free fatty acids into newly synthesized plasma triglycerides. Fractional turnover rates in both pools remained unaltered. The appearance-time for newly synthesized plasma triglycerides after injection of label did not change. These results indicate that chenodeoxycholic acid lowers plasma triglyceride by reducing its synthesis, thereby precluding alternative, and possibly undesired, modes of action, such as impaired secretion or increased peripheral catabolism of endogenous triglyceride. Several biochemical mechanisms may be responsible for this effect, among which stimulation of phospholipid synthesis by bile acids could play a role.