Elevated circulating levels of anandamide after administration of the transport inhibitor, AM404

Andrea Giuffrida,Fernando Rodriguez De Fonseca,Felice Nava,Patrick Loubet-Lescoulié,Daniele Piomelli

doi:10.1016/s0014-2999(00)00786-x

Andrea Giuffrida, Fernando Rodriguez De Fonseca + Show 3 more

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https://doi.org/10.1016/s0014-2999(00)00786-x

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Abstract

The biological actions of the endogenous cannabinoid anandamide are terminated by carrier-mediated transport into neurons and astrocytes, followed by enzymatic hydrolysis. Anandamide transport is inhibited by the compound N-(4-hydroxyphenyl)arachidonylamide (AM404). AM404 potentiates several responses elicited by administration of exogenous anandamide, suggesting that it may also protect endogenous anandamide from inactivation. To test this hypothesis, we studied the effects of AM404 on the plasma levels of anandamide using high-performance liquid chromatography/mass spectrometry (HPLC/MS). Systemic administration of AM404 (10 mg kg −1 intraperitoneal, i.p.) caused a gradual increase of anandamide in rat plasma, which was significantly different from untreated controls at 60 and 120 min after drug injection. In plasma, both AM404 and anandamide were associated with a plasma protein, which we identified as albumin by non-denaturing polyacrylamide gel electrophoresis. AM404 (10 mg kg −1, i.p.) caused a time-dependent decrease of motor activity, which was reversed by the cannabinoid CB 1 receptor antagonist N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1 H-pyrazole-3-carboxamide·hydrochloride (SR141716A, 0.5 mg kg −1, i.p). These results are consistent with the hypothesis that AM404 inhibits anandamide inactivation in vivo.

Highlights

Anandamide is an endogenous derivative of arachidonic acid that binds with high affinity to cannabinoid receptors and mimics virtually all pharmacological actions of plantderived or synthetic cannabinoid drugs ŽDevane et al, 1992
Drugs that interfere with anandamide transport have both theoretical and practical interest
Because of the inability of AM404 to activate cannabinoid receptors ŽBeltramo et al, 1997, 2000., the effects of this drug were suggested to result from the elevation of endogenous anandamide levels

Summary

Introduction

Anandamide is an endogenous derivative of arachidonic acid that binds with high affinity to cannabinoid receptors and mimics virtually all pharmacological actions of plantderived or synthetic cannabinoid drugs ŽDevane et al, 1992. Through a rapid inactivation process consisting of uptake into cells ŽBeltramo et al, 1997; Hillard et al, 1997. Anandamide uptake is a Naq-independent process that fulfills four key criteria that define carried-mediated transport: high affinity, temperature dependence, substrate selectivity and substrate saturation ŽBeltramo et al, 1997; Hillard et al, 1997. Anandamide transport may be pharmacologically inhibited by several compounds, including bromcresol green and N-Ž4-hydroxyphenyl.arachidonylamide ŽAM404. Giuffrida et al.r European Journal of Pharmacology 408 (2000) 161–168

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