Prostaglandins and cannabis--XIII. Cannabinoid-induced elevation of lipoxygenase products in mouse peritoneal macrophages.

The phospholipases controlling the release of arachidonic acid in mouse peritoneal macrophages have been shown to be stimulated by the natural psychoactive cannabinoids. A close correlation was observed between the potencies of these substances in elevating arachidonate levels in vitro and the reported activities in a behavioral assay in monkeys and in producing a "high" in humans. The order of activity with the macrophages was delta 1-tetrahydrocannabinol (delta 1-THC) greater than 7-OH-delta 1-THC greater than 6 alpha-OH-delta 1-THC greater than 6 beta-delta 1-THC much greater than delta 6-THC-7-oic acid. It is suggested that this effect, which has now been shown in several diverse cell types, may serve as a model for studying the mechanism of action of THC.