CANNABIS - PHARMACOLOGY AND TOXICOLOGY IN ANIMALS AND HUMANS

Cannabis is one of the most widely used drugs throughout the world. Th e psychoactive constituent of cannabis, Delta(9)-tetrahydrocannabinol (Delta 9-THC), produces a myriad of pharmacological effects in animals and humans. For many decades, the mechanism of action of cannabinoids , compounds which are structurally similar to Delta(9)-THC, was unknow n. Tremendous progress has been made recently in characterizing cannab inoid receptors both centrally and peripherally and in studying the ro le of second messenger systems at the cellular level. Furthermore, an endogenous ligand, anandamide, for the cannabinoid receptor has been i dentified. Anandamide is a fatty-acid derived compound that possesses pharmacological properties similar to Delta(9)-THC. The production of complex behavioral events by cannabinoids is probably mediated by spec ific cannabinoid receptors and interactions with other neurochemical s ystems. Cannabis also has great therapeutic potential and has been use d for centuries for medicinal purposes. However, cannabinoid-derived d rugs on the market today lack specificity and produce many unpleasant side effects, thus limiting therapeutic usefulness. The advent of high ly potent analogs and a specific antagonist may make possible the deve lopment of compounds that lack undesirable side effects. The advanceme nts in the field of cannabinoid pharmacology should facilitate our und erstanding of the physiological role of endogenous cannabinoids.