Influence of dietary fat on fatty livers of choline-deficient rats.

Our purpose was to evaluate the influence of type of dietary fat on nature and severity of liver lipid changes induced in male weanling rats by low choline diets. Beef tallow, a blend of tallow and safflower oil (SO) each provided 48% of total energy value of a control diet and a low choline diet. Livers from choline-deficient rats fed tallow, blend, or SO diets contained approximately 4.5, 5, and 2.5 times as much lipid, respectively, as livers from corresponding control groups. Liver lipids from rats fed SO diets as compared with those from rats fed tallow diets contained lower percentages of saturated and monounsaturated fatty acids, and higher percentages of polyunsaturated fatty acids. Values for groups fed blend diets were intermediate, except for 18:0 and 20:4 in the control group. Choline deficiency resulted in significant increases in proportions of the predominant fatty acid(s) of the dietary fat in liver lipids (but not in fat pad lipids) at the expense of 18:0 and 20:4. Ratios of 16:0 to 18:0 in both liver and fat pad lipids were greater in choline-deficient than in corresponding control groups, probably reflecting greater fatty acid synthesis.