title: Smoking normalizes cerebral blood flow and oxygen consumption after 12-hour abstention.
abstract: Acute nicotine administration stimulates [(14)C]deoxyglucose trapping in thalamus and other regions of rat brain, but acute effects of nicotine and smoking on energy metabolism have rarely been investigated in human brain by positron emission tomography (PET). We obtained quantitative PET measurements of cerebral blood flow (CBF) and metabolic rate of oxygen (CMRO2) in 12 smokers who had refrained from smoking overnight, and in a historical group of nonsmokers, testing the prediction that overnight abstinence results in widespread, coupled reductions of CBF and CMRO2. At the end of the abstention period, global grey-matter CBF and CMRO2 were both reduced by 17% relative to nonsmokers. At 15 minutes after renewed smoking, global CBF had increased insignificantly, while global CMRO2 had increased by 11%. Regional analysis showed that CMRO2 had increased in the left putamen and thalamus, and in right posterior cortical regions at this time. At 60 and 105 minutes after smoking resumption, CBF had increased by 8% and CMRO2 had increased by 11-12%. Thus, we find substantial and global impairment of CBF/CMRO2 in abstaining smokers, and acute restoration by resumption of smoking. The reduced CBF and CMRO2 during acute abstention may mediate the cognitive changes described in chronic smokers.
authors.affiliation: Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Manouchehr S
authors.initials: MS
authors.lastname: Vafaee
authors.affiliation: 1] Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark [2] Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Albert
authors.initials: A
authors.lastname: Gjedde
authors.affiliation: Department of Pulmonary Medicine, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Nasrin
authors.initials: N
authors.lastname: Imamirad
authors.affiliation: Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Kim
authors.initials: K
authors.lastname: Vang
authors.affiliation: Department of Psychiatry and Biomedical Engineering, Cerebral Imaging Centre, Douglas Mental Health Institute, McGill University, Montreal, Quebec, Canada.
authors.forename: Mallar M
authors.initials: MM
authors.lastname: Chakravarty
authors.affiliation: Program in Neuroscience and Mental Health, The Hospital for Sick Children, Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Jason P
authors.initials: JP
authors.lastname: Lerch
authors.affiliation: Department of Nuclear Medicine, Universitätsklinik Erlangen/Nurenberg, Erlangen, Germany.
authors.forename: Paul
authors.initials: P
authors.lastname: Cumming
mesh_terms: D000328:Adult; D001921:Brain / Q000033:anatomy & histology / Q000098:blood supply* / Q000378:metabolism*; D002560:Cerebrovascular Circulation; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D008297:Male; D010100:Oxygen / Q000378:metabolism; D010101:Oxygen Consumption; D049268:Positron-Emission Tomography; D012907:Smoking / Q000378:metabolism*; D055815:Young Adult
chemical_list: D010100:Oxygen