Background and purpose: Cannabis is the source of at least seventy phytocannabinoids. The pharmacology of most of these has been little investigated, three notable exceptions being D9 -tetrahydrocannabinol, cannabidiol and D9 -tetrahydrocannabivarin. This investigation addressed the question of whether the little-studied phytocannabinoid, cannabigerol, can activate or block any G protein-coupled receptor. Experimental approach: The [35S]GTPgS binding assay, performed with mouse brain membranes, was used to test the ability of cannabigerol to produce G protein-coupled receptor activation or blockade. Its ability to displace [3 H]CP55940 from mouse CB1 and human CB2 cannabinoid receptors and to inhibit electrically evoked contractions of the mouse isolated vas deferens...
