Faculty Collaboration Database

The uptake by cells of 2-arachidonoylglycerol, an endogenous agonist of cannabinoid receptors. Eur J Biochem 2001 Apr;268(7):1982-9

Date

03/30/2001

Pubmed ID

11277920

DOI

10.1046/j.1432-1327.2001.02072.x

Scopus ID

2-s2.0-0034850220 (requires institutional sign-in at Scopus site)   138 Citations

Abstract

It is not yet clear if the endocannabinoid 2-arachidonoylglycerol (2-AG) is transported into cells through the same membrane transporter mediating the uptake of the other endogenous cannabinoid, anandamide (N-arachidonoylethanolamine, AEA), and whether this process (a) is regulated by cells and (b) limits 2-AG pharmacological actions. We have studied simultaneously the facilitated transport of [14C]AEA and [3H]2-AG into rat C6 glioma cells and found uptake mechanisms with different efficacies but similar affinities for the two compounds (Km 11.0 +/- 2.0 and 15.3 +/- 3.1 microM, Bmax 1.70 +/- 0.30 and 0.24 +/- 0.04 nmol.min-1.mg protein-1, respectively). Despite these similar Km values, 2-AG inhibits [14C]AEA uptake by cells at concentrations (Ki = 30.1 +/- 3.9 microM) significantly higher than those required to either 2-AG or AEA to inhibit [3H]2-AG uptake (Ki = 18.9 +/- 1.8 and 20.5 +/- 3.2 microM, respectively). Furthermore: (a) if C6 cells are incubated simultaneously with identical concentrations of [14C]AEA and [3H]2-AG, only the uptake of the latter compound is significantly decreased as compared to that observed with [3H]2-AG alone; (b) the uptake of [14C]AEA and [3H]2-AG by cells is inhibited with the same potency by AM404 (Ki = 7.5 +/- 0.7 and 10.2 +/- 1.7 microM, respectively) and linvanil (Ki = 9.5 +/- 0.7 and 6.4 +/- 1.2 microM, respectively), two inhibitors of the AEA membrane transporter; (c) nitric oxide (NO) donors enhance the uptake of both [14C]AEA and [3H]2-AG, thus suggesting that 2-AG action can be regulated through NO release; (d) AEA and 2-AG induce a weak release of NO that can be blocked by a CB1 cannabinoid receptor antagonist, and significantly enhanced in the presence of AM404 and linvanil, thus suggesting that transport into C6 cells limits the action of both endocannabinoids.

Author List

Bisogno T, MacCarrone M, De Petrocellis L, Jarrahian A, Finazzi-Agrò A, Hillard C, Di Marzo V

Author

Cecilia J. Hillard PhD Associate Dean, Center Director, Professor in the Pharmacology and Toxicology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Arachidonic Acids
Biological Transport, Active
Cannabinoid Receptor Modulators
Cell Membrane
Endocannabinoids
Glioma
Glycerides
Kinetics
Models, Chemical
Neurotransmitter Agents
Nitric Oxide
Polyunsaturated Alkamides
Rats
Receptors, Cannabinoid
Receptors, Drug
Tumor Cells, Cultured