Delta(9)-Tetrahydrocannabinol-like discriminative stimulus effects of compounds commonly found in K2/Spice
BEHAVIOURAL PHARMACOLOGY
Authors: Gatch, Michael B.; Forster, Michael J.
Abstract
A number of cannabinoid compounds are being sold in the form of incense as 'legal' alternatives to marijuana. The purpose of these experiments was to determine whether the most common of these compounds have discriminative stimulus effects similar to. 9-tetrahydrocannabinol (Delta(THC)-T-9), the main active component in marijuana. Locomotor depressant effects of JWH-018, JWH-073, JWH-200, JWH-203, JWH-250, AM-2201, and CP 47,497-C8-homolog were tested in mice. The compounds were then tested for substitution in rats trained to discriminate Delta(9)-THC (3 mg/kg, intraperitoneally). The time course of the peak dose of each compound was also tested. Each of the synthetic cannabinoids dose-dependently decreased locomotor activity for 1-2 h. Each of the compounds fully substituted for the discriminative stimulus effects of Delta(9)-THC, mostly at doses that produced only marginal amounts of rate suppression. JWH-250 and CP 47,497-C8-homolog suppressed response rates at doses that fully substituted for Delta(9)-THC. The time courses varied markedly between compounds. Most of the compounds had a shorter onset than Delta(9)-THC, and the effects of three of the compounds lasted substantially longer (JWH-073, JWH-250, and CP 47,497-C8-homolog). Several of the most commonly used synthetic cannabinoids produce behavioral effects comparable with those of Delta(9)-THC, which suggests that these compounds may share the psychoactive effects of marijuana responsible for abuse liability. The extremely long time course of the discriminative stimulus effects and adverse effects of CP 47,497-C8-homolog suggest that CP 47,497-C8-homolog may be associated with increased hazards among humans. (C) 2014 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.
Conjugation of Synthetic Cannabinoids JWH-018 and JWH-073, Metabolites by Human UDP-Glucuronosyltransferases
DRUG METABOLISM AND DISPOSITION
Authors: Chimalakonda, Krishna C.; Bratton, Stacie M.; Le, Vi-Huyen; Yiew, Kan Hui; Dineva, Anna; Moran, Cindy L.; James, Laura P.; Moran, Jeffery H.; Radominska-Pandya, Anna
Abstract
K2, a synthetic cannabinoid (SC), is an emerging drug of abuse touted as "legal marijuana" and marketed to young teens and first-time drug users. Symptoms associated with K2 use include extreme agitation, syncope, tachycardia, and visual and auditory hallucinations. One major challenge to clinicians is the lack of clinical, pharmacological, and metabolic information for the detection and characterization of K2 and its metabolites in human samples. Information on the metabolic pathway of SCs is very limited. However, previous reports have shown the metabolites of these compounds are excreted primarily as glucuronic acid conjugates. Based on this information, this study evaluates nine human recombinant uridine diphosphate-glucuronosyltransferase (UGT) isoforms and human liver and intestinal microsomes for their ability to glucuronidate hydroxylated metabolites of 1-naphthalenyl-1(1-pentyl-1H-indol-3-yl)-methanone (JWH-018) and (1-butyl-1H-indol-3-yl)-1-naphthalenyl-methanone (JWH-073), the two most common SCs found in K2 products. Conjugates were identified and characterized using liquid chromatography/tandem mass spectrometry, whereas kinetic parameters were quantified using high-performance liquid chromatography-UV-visible methods. UGT1A1, UGT1A3, UGT1A9, UGT1A10, and UGT2B7 were shown to be the major enzymes involved, showing relatively high affinity with K-m ranging from 12 to 18 mu M for some hydroxylated K2s. These UGTs also exhibited a high metabolic capacity for these compounds, which indicates that K2 metabolites may be rapidly glucuronidated and eliminated from the body. Studies of K2 metabolites will help future development and validation of a specific assay for K2 and its metabolites and will allow researchers to fully explore their pharmacological actions.