AJP - Gastrointestinal and Liver Physiology, Vol 242, Issue 5 493-G497, Copyright © 1982 by American Physiological Society
Metabolism of arachidonic acid by pancreatic acini: relation to amylase secretion
W. F. Stenson and E. Lobos
Isolated guinea pig pancreatic acini were incubated with exogenous
[14C]arachidonic acid (10 microM) at 37 degrees C for 3 min. The lipids
were extracted and separated by thin-layer chromatography. Radiolabeled
metabolites were identified by comigration with standards: 0.024% of the
recovered radioactivity comigrated with prostaglandin E2 (PGE2), 0.016%
comigrated with PGF2 alpha, 4.9% was incorporated into triglycerides, 1.8%
was incorporated into phospholipids, and 93.2% remained as arachidonic
acid. The synthesis of PGE2 and PGF2 alpha was inhibited by indomethacin
(ID50, 30 nM). Simultaneous addition of carbachol or caerulein with the
[14C]arachidonic acid did not alter the metabolism of the arachidonate.
Further studies were done on the role of arachidonate metabolites in the
secretion of amylase. Exogenously added PGE2 and PGF2 alpha (0.3-100 nM)
did not induce amylase secretion from isolated acini. Incubation of
isolated acini with indomethacin (0.1-28 microM) did not inhibit the
release of amylase induced by carbachol or caerulein. From these data, we
conclude that isolated guinea pig pancreatic acini are capable of
converting a small percentage of exogenous arachidonate to PGE2 and PGF2
alpha. However, there is no evidence for a role of these compounds in
stimulus-secretion coupling.
