Regulation of apolipoprotein secretion and lipid synthesis by fatty acids in a newborn swine intestinal epithelial cell line. Wang, Heng, Helen M. Berschneider, Jianhui Du, and Dennis D. Black. Department of Pediatrics, Arkansas Children's Hospital Research Institute, University of Arkansas for Medical Sciences, Little Rock, AR 72202 and
APStracts 3:0224G, 1996.
The IPEC-1 newborn swine intestinal epithelial cell line was used to determine the effects of the uptake of various fatty acids on the secretion of apo B and A-I, as well as triglyceride and phospholipid. Long-chain saturated fatty acids were taken up and stimulated triglyceride synthesis, and palmitic (16:0) and stearic (18:0) acids also stimulated phospholipid synthesis. However, these fatty acids did not enhance triglyceride, phospholipid, or apo B or A-I secretion. Oleic acid (18:1) was the most effective of all fatty acids tested in stimulating triglyceride synthesis and the secretion of triglyceride, phospholipid, and apo B. Linoleic (18:2) and linolenic (18:3) acids were no more effective than long-chain saturated fatty acids in stimulating these processes. With saturated fatty acids, apo A-I followed the same secretory pattern as apo B. However, among the unsaturated fatty acids, oleic acid was the least effective and linolenic acid was the most effective in stimulating apo A-I secretion. Basolateral secretion of lipid and apolipoproteins by differentiated IPEC-1 cells is differentially regulated by apical exposure to fatty acids.

Received 9 July 1996; accepted in final form 10 October 1996.
APS Manuscript Number G272-6.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 5 November 1996