Preventive and curative studies on the cholesterol fatty liver of rats.

Phospholipid was the only fraction which appeared to be relatively constant in its rate of deposition. The effect of increasing the concentration of cholesterol in the diet of male rats may be seen in Fig. 2, where data for total liver lipids and for cholesteryl esters are presented as percentage of fresh liver weight. More complete data about the composition of these livers are available in Table 2. The increases which occurred in each component were calculated (as in Table 1) and the percentage composition of the material deposited in the livers under each of the dietary regimens was calculated. These data are shown in Table 3. Again it may be seen that regardless of the amount of cholesterol in the diet, the material deposited in the liver consists principally of glycerides and of water. As might be anticipated, the deposition of cholesteryl esters increases with increasing amounts of dietary cholesterol. In these male animals the cholesteryl esters continued to rise throughout the period of observation. At the start of the experiment, the absolute amount of free cholesterol was about 10 mg. and that of cholesteryl esters about 3 mg., making a total of 13 mg. (cf. Table 2). In the case of rats consuming the diet containing 0-8 % cholesterol, the absolute amounts of free cholesterol at 21 and 90 days were 20 and 66 mg., respectively, and the corresponding values for cholesteryl esters were 209 and 1278 mg. Since the liver gained 5.53 g. in weight in the first 21 days and cholesterol plus esters account for 216 mg. of this, they represent 3.9 % of the material deposited in this interval (cf. Table 3). When rats were maintained on the same diet for a total of 90 days the cholesterol plus ester portion increased to 10 1 % ofthe material deposited during the period of 21-90 days. The female rats used in the first experiment did not exhibit the same increase. Actually, in female rats, the rate at which cholesteryl esters were accumulating dlecreased with time (after 21 days). SUMMARY