Linoleic and linolenic acids are selectively secreted in
triacylglycerol by hepatocytes from neonatal rats.
Emmison, Neil, Patricia A. Gallagher, and Rosalind A Coleman.
Department of Nutrition, Schools of Public Health and Medicine,
University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
-7400
APStracts 2:0039R, 1995.
To determine whether specific fatty acids are metabolized differently
by neonatal liver, hepatocyte cultures from neonatal (aged 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, 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 to
that which accumulated in the cells, was 2-4-fold higher for day-11
and day-21 rat hepatocytes. The results suggest that a specific
mechanism exists in the livers of neonatal rats to spare omega-3 and
omega-6 fatty acids from oxidation and instead secrete them in
triacylglycerol.
Received 30 June 1994; accepted in final form 22 January 1995.
APS Manuscript Number R373-4.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 25 February 1995.