Increased cholesteryl ester content in liver of mice fed lipid emulsion diets high in polyunsaturated fats

Mice were fed a liquid diet containing different fat sources for 6 days and several biochemical parameters in the liver were examined. Mice fed diets containing Nutralipid or Liposyn as 45% of total calories had 30.5 +/- 2.5 and 25.8 +/- 3.7 nmol cholesteryl esters per milligram liver protein, respectively, as compared with 13.14 +/- 2.4 for those fed regular mouse food and 13.7 +/- 2.45 for those fed an emulsion containing mostly triolein as fat source. A similar increase in liver cholesteryl esters resulting from estrogen treatment has been proposed as the basis for changes resulting in decreased bile flow in the rat. It is suggested that the high content of polyunsaturated fatty acids in nutrient emulsions might be responsible for cholestasis sometimes observed in patients receiving these preparations. This is further supported by the observation that, as in the case of estrogen treatment, the cholesteryl ester level returned to normal when mice were treated with the detergent Triton WR-1339.