title: The effect of prolonged exposure to morphine on canine cerebral 5-HT2A receptors measured with (123)I-R91150 SPECT.
abstract: Down-stream neuronal alterations, including changes in the 5-HT-2A receptor system, play an important role in the etiology and treatment of depression. The present study examined the effect of prolonged opioid treatment on cerebral 5-HT2A receptors. Cerebral 5-HT2A receptor availability was estimated in seven healthy five-year-old female neutered Beagle dogs pre and post 10-day morphine treatment (oral sustained release morphine 20mg twice daily for 10 days) with (123)I-R-91150, a 5-HT2A selective radioligand, and SPECT. 5-HT2A receptor binding indices (BI) for the frontal, parietal, temporal and occipital cortex and the subcortical region were calculated. Statistical analysis was performed using a linear mixed-effect model with treatment as fixed effect and dog as random effect. Morphine treatment significantly (P≤0.05) lowered 5-HT2A BIs in the right and left frontal cortex, the right and left temporal cortex, the right and left parietal cortex, and the subcortical region. The decreased cerebral 5-HT2A receptor availability following prolonged morphine exposure provides further evidence for an interaction between the opioid and serotonergic system.
authors.affiliation: Medicine and Clinical Biology of Small Animals, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
authors.forename: Antita
authors.initials: A
authors.lastname: Adriaens
authors.affiliation: Medicine and Clinical Biology of Small Animals, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium. Electronic address: Ingeborgh.polis@UGent.be.
authors.forename: Ingeborgh
authors.initials: I
authors.lastname: Polis
authors.affiliation: Medical Imaging of Domestic Animals, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors.forename: Simon
authors.initials: S
authors.lastname: Vermeire
authors.affiliation: Medicine and Clinical Biology of Small Animals, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
authors.forename: Tim
authors.initials: T
authors.lastname: Waelbers
authors.affiliation: Pharmacology, Biochemistry and Toxicology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors.forename: Siska
authors.initials: S
authors.lastname: Croubels
authors.affiliation: Physiology and Biometry, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors.forename: Luc
authors.initials: L
authors.lastname: Duchateau
authors.affiliation: Drug Quality & Registration (DruQuaR) Group, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Van Dorpe
authors.affiliation: Nuclear Medicine and PET Research, VU University Medical Centre, Amsterdam, The Netherlands.
authors.forename: Jos
authors.initials: J
authors.lastname: Eersels
authors.affiliation: Drug Quality & Registration (DruQuaR) Group, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium.
authors.forename: Bart
authors.initials: B
authors.lastname: De Spiegeleer
authors.affiliation: Medical Imaging of Domestic Animals, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors.forename: Kathelijne
authors.initials: K
authors.lastname: Peremans
mesh_terms: D000818:Animals; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000378:metabolism; D004285:Dogs; D005260:Female; D009020:Morphine / Q000494:pharmacology*; D009294:Narcotics / Q000494:pharmacology*; D011877:Radionuclide Imaging; D044402:Receptor, Serotonin, 5-HT2A / Q000378:metabolism*
chemical_list: D009294:Narcotics; D044402:Receptor, Serotonin, 5-HT2A; D009020:Morphine
keywords: (123)I-R91150; 5-HT2A; Dogs; Morphine; SPECT