title: Effects of tetrahydrocannabinol on glucose uptake in the rat brain.
abstract: Δ9-Tetrahydrocannabinol (THC) is the psychoactive component of the plant Cannabis sativa and acts as a partial agonist at cannabinoid type 1 and type 2 receptors in the brain. The goal of this study was to assess the effect of THC on the cerebral glucose uptake in the rat brain. 21 male Sprague Dawley rats (12-13 w) were examined and received five different doses of THC ranging from 0.01 to 1 mg/kg. For data acquisition a Focus 120 small animal PET scanner was used and 24.1-28.0 MBq of [18F]-fluoro-2-deoxy-d-glucose were injected. The data were acquired for 70 min and arterial blood samples were collected throughout the scan. THC, THC-OH and THC-COOH were determined at 55 min p.i. Nine volumes of interest were defined, and the cerebral glucose uptake was calculated for each brain region. Low blood THC levels of < 1 ng/ml (injected dose: ≤ 0.01 mg/kg) corresponded to an increased glucose uptake (6-30 %), particularly in the hypothalamus (p = 0.007), while blood THC levels > 10 ng/ml (injected dose: ≥ 0.05 mg/kg) coincided with a decreased glucose uptake (-2 to -22 %), especially in the cerebellar cortex (p = 0.008). The effective concentration in this region was estimated 2.4 ng/ml. This glucose PET study showed that stimulation of CB1 receptors by THC affects the glucose uptake in the rat brain, whereby the effect of THC is regionally different and dependent on dose - an effect that may be of relevance in behavioural studies.
authors.affiliation: Department of Nuclear Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstraße 1, 55131 Mainz, Germany. Electronic address: isabelle.miederer@unimedizin-mainz.de.
authors.forename: I
authors.initials: I
authors.lastname: Miederer
authors.affiliation: Institute of Legal Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Am Pulvertum 3, 55131 Mainz, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Uebbing
authors.affiliation: Institute of Legal Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Am Pulvertum 3, 55131 Mainz, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Röhrich
authors.affiliation: Department of Nuclear Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstraße 1, 55131 Mainz, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Maus
authors.affiliation: Department of Nuclear Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstraße 1, 55131 Mainz, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Bausbacher
authors.affiliation: Institute of Legal Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Am Pulvertum 3, 55131 Mainz, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Krauter
authors.affiliation: Institute of Medical Biostatistics, Epidemiology and Informatics, University Medical Center of the Johannes Gutenberg University Mainz, Obere Zahlbacher Straße 69, 55131 Mainz, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Weyer-Elberich
authors.affiliation: Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, 55128 Mainz, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Lutz
authors.affiliation: Department of Nuclear Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstraße 1, 55131 Mainz, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Schreckenberger
authors.affiliation: Institute of Legal Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Am Pulvertum 3, 55131 Mainz, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Urban
mesh_terms: D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000378:metabolism*; D001931:Brain Mapping; D063386:Cannabinoid Receptor Agonists / Q000097:blood / Q000493:pharmacokinetics / Q000494:pharmacology*; D002853:Chromatography, Liquid; D004305:Dose-Response Relationship, Drug; D013759:Dronabinol / Q000097:blood / Q000493:pharmacokinetics / Q000494:pharmacology*; D019788:Fluorodeoxyglucose F18; D005947:Glucose / Q000378:metabolism*; D008297:Male; D049268:Positron-Emission Tomography; D011619:Psychotropic Drugs / Q000097:blood / Q000493:pharmacokinetics / Q000494:pharmacology*; D019275:Radiopharmaceuticals; D017207:Rats, Sprague-Dawley; D053719:Tandem Mass Spectrometry
chemical_list: D063386:Cannabinoid Receptor Agonists; D011619:Psychotropic Drugs; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D013759:Dronabinol; D005947:Glucose
keywords: Dronabinol (PubChem CID:16078); Rat; THC; [(18)F]-fluoro-2-deoxy-d-glucose (PubChem CID: 3232583); [(18)F]FDG; microPET