title: Cannabichromene and tetrahydrocannabinol determination in mouse blood and brain by gas chromatography-mass spectrometry.
abstract: Cannabichromene (CBC) is a phytocannabinoid, the second most abundant cannabinoid quantitatively in marijuana. CBC has been shown to produce antinociception and anti-inflammatory effects in rodents. This method is validated for the measurement of THC and CBC simultaneously after extraction from mouse blood or brain. Whole brain harvested from mice was homogenized 2:1 (v/w) with normal saline. Fifty nanograms of THC-d₃ was added to 0.5 mL of heparinized mouse blood, brain homogenate, and THC and CBC fortified blood or brain calibrators, then equilibrated overnight at 5 °C. Two milliliters of "ice cold" acetonitrile was added drop-wise while the sample was vortex mixed, and then the sample was centrifuged and stored overnight at -30 °C. The cannabinoids were extracted from the acetonitrile layer with 2 mL of 0.2 N NaOH and 4 mL of hexane/ethyl acetate (9:1). The solvent was isolated and evaporated to dryness. Trimethylsilyl derivatives were prepared and then analyzed by gas chromatography-mass spectrometry. Linearity in blood and brain of THC and CBC was 2-10,000 ng/mL (ng/g). THC and CBC recovery ranged from 56 to 78% in blood and brain. Precision was demonstrated at 100 ng/mL and 1000 ng/mL with CVs < 15%. The validated method allows for blood and brain concentrations of cannabinoids to be quantificated and correlated with pharmacological effects produced in mice.
authors.affiliation: Occupational and Environmental Health Sciences Division, Department of Preventive Medicine and Biometrics, Uniformed Services University of the Health Services, Bethesda, Maryland, USA.
authors.forename: Gerald T
authors.initials: GT
authors.lastname: DeLong
authors.forename: Carl E
authors.initials: CE
authors.lastname: Wolf
authors.forename: Alphonse
authors.initials: A
authors.lastname: Poklis
authors.forename: Aron
authors.initials: A
authors.lastname: Lichtman
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D002138:Calibration; D002186:Cannabinoids / Q000097:blood* / Q000493:pharmacokinetics; D013759:Dronabinol / Q000097:blood* / Q000493:pharmacokinetics; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D057230:Limit of Detection; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D012015:Reference Standards; D015203:Reproducibility of Results; D015813:Substance Abuse Detection / Q000379:methods*
chemical_list: D002186:Cannabinoids; D013759:Dronabinol; C010695:cannabichromene