Activity of Δ 8 - and Δ 9 -Tetrahydrocannabinol and Related Compounds in the Mouse

Abstract
The 11-hydroxy metabolites of Δ8.- and Δ9-tetrahydrocannabinol are more active than the parent compounds when administered to mice by either the intravenous or intracerebral route. Both Δ8- and Δ9-tetrahydrocannabinol are rapidly and extensively metabolized by the liver and not by the brain. The hypothesis that the 11-hydroxy metabolites may be the active form of tetrahydrocannabinol is discussed