The Effect of Choline Supplementation on Hepatic Steatosis in the Parenterally Fed Rat

Abstract

Information regarding hepatic function during total parenteral nutrition in rats is often extrapolated to the clinical situation, but the steatosis observed in that species may simply reflect choline deficiency and be irrelevant to man. The effect of choline supplementation on hepatic lipid content and triglyceride secretion was examined in parenterally fed rats. Eighty to 90-day-old rats were randomized into three groups; group I received oral Purina Chow ad libitum, groups II and III received identical total parenteral nutrition regimens with the exception that group III received supplemental choline. After 7 days, peripheral triglyceride uptake was inhibited with Triton WR1339, the rate of secretion of ¹⁴C-labeled triglyceride measured after a bolus injection of 1-¹⁴C-palmitic acid, and total hepatic lipid content was measured. Total hepatic lipid content was elevated in group II (86.3 mg/g) and group III (83.3 mg/g), and both differed significantly from the control group I (35.2 mg/g, p < 0.01), but the choline supplementation appeared to make no difference. Hepatic secretion of ¹⁴C-palmitic acid as ¹⁴C-triglyceride was reduced in group II (0.73%/ml plasma), and group III (0.72%/ml plasma) compared to group I (1.06%/ ml plasma, p < 0.05), and was unaffected by choline. The hepatic steatosis produced in the parenterally fed rat did not appear to be due to choline deficiency but to some other factors which may be important in man. (Journal of Parenteral and Enteral Nutrition 9:597-599, 1985)