The IPEC-1 enterocyte line was derived from a newborn unsuckled piglet. The aim of these studies was to characterize the secretion of apolipoproteins(apo) B and A-I by these cells in response to incubation with various fatty acids (FA). FA/albumin complexes were added to apical culture medium of differentiated cells (0.8 mM). After 24 hrs, basolateral apolipoprotein secretion was measured: Figure The mechanism of increased apolipoprotein secretion in response to oleic acid (18:1, OA) was investigated by pulse-chase radiolabelling with 35S-methionine during the final 4 hrs of a 24 hr incubation with OA/albumin and albumin alone. Analysis of labelling kinetics for apo B and A-I revealed no differences in synthesis or degradation. Conclusions: With increasing chain length, saturated FA decrease apo B and A-I secretion by IPEC-1 cells. Among long-chain unsaturated FA, OA stimulates the greatest apo B secretion, and apo A-I secretion increases with decreasing saturation. Increased secretion in response to OA may involve a preformed intracellular pool of apolipoprotein with slow turnover.

figure 1

Figure 1