The results for the esterification of [1-14C]-labelled fatty acids into
different classes of lipids in the SBT-E1 cells are shown in Fig. 2. Most
of the fatty acids, other than 20:5n−3, were incorporated predominantly
into PC. In the case of 20:5n−3, there was approximately
equal incorporation into PC and PE. The label recovered in PC ranged
from approximately 50% to a little more than 60% of the total for all of
the fatty acids except 20:5n−3. Nearly 80% of the label from
20:5n−3 was recovered in both PC and PE with approximately 40% in
each. When the fatty acid esterification data were expressed relative
to the lipid class abundance data, therewas clear preferential incorporation
of 16:0 into PC and SM, 18:1n−9 into PC and PS and 18:2n−6 into
PC and PA/CL (data not shown). The results for 18:3n−3 were similar
to those for 18:2n−6 though not as pronounced. Thisway of expressing
the data also showed preferential incorporation of 20:5n−3 into PE
over PC.