Caerulein-stimulated arachidonic acid release in rat pancreatic
acini : a diacylglycerol lipase affair.
Hou, Wei, Yoshiyuki Arita, and Jean Morisset.
D[acute]epartement de M[acute]edecine, Facult[acute]e de
M[acute]edecine, Universit[acute]e de Sherbrooke, Sherbrooke,
Qu[acute]ebec, Canada J1H 5N4
APStracts 3:0152C, 1996.
This study was performed to evaluate the effect of caerulein, a
cholecystokinin analog, on arachidonic acid (AA) release in rat
pancreatic acini and determine the cellular mechanism involved.
Caerulein did not stimulate phospholipase A2 (PLA2) while increasing
diacylglycerol (DAG) lipase activity. Validity of PLA2 or DAG lipase
inhibitors was confirmed by their ability to selectively inhibit PLA2
or DAG lipase activities. Caerulein increased AA release from acini
prelabeled with [3H]-AA dose- and time-dependently. Inhibitors were
used to evaluate the involvement of different signaling pathways.
Mepacrine and aristolochic acid, two PLA2 inhibitors, did not inhibit
caerulein-induced AA release while the DAG lipase inhibitor RHC 80267
did. The phospholipase C inhibitor U73122 totally inhibited
caerulein-induced AA release whereas the phospholipase D inhibitor
wortmannin had no effect. Our data indicate that caerulein-induced AA
release results from the combined action of PLC and DAG lipase
without PLA2 nor PLD activation.
Received 18 March 1996; accepted in final form 2 May 1996.
APS Manuscript Number C153-6.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 28 May 96