Metabolism of tetrahydrocannabinol (THC) (WP4174)
Pathway visualizing part of THC metabolism. Delta9-tetrahydrocannabinol (THC, also named delta1-tetrahydrocannabinol), is the primary hallucinogenic constituent of Cannabis sativa (plant) a.k.a. marijuana. Different parts of the plant contain varying concentrations of THC, with leaves containing <1% to 10% THC by weight, and hashish, a resin prepared from the flowering tops, containing approximately 15% THC. This drug undergoes various transformation in the Phase I (mainly hepatic metabolism primarily by hydroxylation), after which several metabolites can be transformed via Phase II reactions (such as acyl glucuronidatization). THC possesses activity at benzodiazepine, opioid, and cannabinoid receptors and also exerts effects on prostaglandin synthesis, DNA, RNA, and protein metabolism. Furthermore, THC work on the two types of cannabinoid receptor that exist in the human body — CB1 and CB2 — and these receptors are the primary targets of endogenous cannabinoids (endocannabinoids). THC binds to both cannabinoid receptors. The CB1 receptor is mostly found in the brain, while the CB2 receptor is found in immune tissues such as the spleen, thymus, and tonsils (but not in the brain). Specific antagonists exist for each of the CB1 and CB2 receptors. Cannabinoid-coupled G protein–coupled receptors are involved in the control of many processes, including metabolic regulation, craving, pain, anxiety, bone growth, and immune function.
AuthorsDenise Slenter , Kristina Hanspers , Egon Willighagen , Eric Weitz , Alex Pico , and Lars Willighagen
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Pathway Ontologyxenobiotic metabolic pathway drug pathway phase I biotransformation pathway via cytochrome P450
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