To determine whether specific fatty acids are metabolized differently by neonatal liver, hepatocyte cultures from neonatal (age: 5, 11, and 21 days) and adult rats were incubated with radiolabeled 18:1, 18:2, or 18:3. At each age, the rate of oxidation was highest for 18:3 and lowest for 18:1. Conversely, esterification was highest for 18:1 and lowest for 18:3. Fatty acid esterification was of the order: day 5 > day 11 > adult > day 21. When incubations contained each of two of the above fatty acids, one radiolabeled and the other not, 18:1 inhibited oxidation of radiolabeled 18:2 by up to 45% in neonatal hepatocytes. In addition, added 18:1 increased glycerolipid accumulation from 18:2 and 18:3. Under these conditions, the relative proportion of triacylglycerol secreted in the medium, compared with that accumulated in the cells, was two- to fourfold higher for day 11 and 21 rat hepatocytes. The results suggest that a specific mechanism exists in the livers of neonatal rats to spare n-3 and n-6 fatty acids from oxidation and instead secrete them in triacylglycerol.
- Copyright © 1995 the American Physiological Society