Alterations in the metabolism of fats and phosphatides in rat liver induced by halide ions.

The effects of halide ions on several pathways of lipid metabolism have been investigated in rat liver slices. Through the use of carboxyl-14-C-labeled acetate and palmitate and U-14-C-labeled glycine, striking differences were found when the effects of the four halide ions on the labeling of the lipids were compared. Both fluoride and iodide dpressed [14-C]acetate incorporation into phosphatide and triglyceride fractions. The effects of the halide ions on the labeling from the effects observed when [14-C]acetate was the precursor of the lipid molecule. In contrast with the phospholipid fractions, the level of radioactivity from [14-C]palmitate incorporated into the triglycerides was lower with fluoride than with chloride. The incorporation of [14-C]glycine into the phospholipids was also greatly depressed by fluoride. The effects of halide ions on acetoacetate formation, on 14-CO2 production and on the acetylcoenzyme A synthetase of rat liver were also investigated. Decreasing [I-14-C]-acetate conversion to acetoacetate iodide had an opposite effect on 14-CO2 production from the same labeled substrate. The effects of the four halide ions and the differences observed with the three labeled substrates on several pathways related to lipid metabolism are discussed.