T. Sugiura et al., 2-ARACHIDONOYLGLYCEROL, A PUTATIVE ENDOGENOUS CANNABINOID RECEPTOR-LIGAND, INDUCES RAPID, TRANSIENT ELEVATION OF INTRACELLULAR FREE CA2-15 CELLS( IN NEUROBLASTOMA X GLIOMA HYBRID NG108), Biochemical and biophysical research communications, 229(1), 1996, pp. 58-64
Low concentrations of 2-arachidonoylglycerol were found to induce rapi
d, transient elevation of intracellular free Ca2+ in NG108-15 cells (E
C(50) was 150 nM). Free arachidonic acid, 2-palmitoylglycerol, 2-oleoy
lglycerol, 2-linoleoylglycerol and 2-docosahexaenoylglycerol were inac
tive. Anandamide acted as a partial agonist. Importantly, desensitizat
ion was observed upon sequential challenge with 2-arachidonoylglycerol
. Furthermore, cross-desensitization was observed between 2-arachidono
ylglycerol and WIN 55212-2, a cannabinoid receptor agonist. Pretreatme
nt of the cells with SR141716A, a cannabinoid receptor antagonist, abo
lished the activities of both 2-arachidonoylglycerol and WIN 55212-2.
These results strongly suggest that 2-arachidonoylglycerol and WIN 552
12-2 bind to a common cannabinoid receptor to elicit cellular response
s and that ?2-arachidonoylglycerol has some physiological role in nerv
ous tissues. (C) 1996 Academic Press, Inc.