Acute effects of cigarette smoking on global cerebral blood flow (GCBF) in overnight abstinent tobacco smokers

Background/Aims The acute effects of tobacco smoking on gCBF were studied. Methods Positron emission tomography (PET) with H215O was used to measure quantitatively CBF in 10 right handed male volunteer tobacco smokers. After 12 hr abstinence, gCBF measurements (baseline, 5% CO2/95% O2, and cigarette smoking) were made. gCBF was adjusted based on the vascular reactivity to CO2 and PaCO2 during smoking. Results Mean gCBF during smoking compared with baseline did not change. However, an increase in nicotine arterial plasma correlated inversely with gCBF; gCBF increased in seven, decreased in seven, and was unchanged in five sessions. gCBF increased during smoking when baseline gCBF was low, whereas gCBF decreased when baseline gCBF was high. Conclusions Individual differences suggest important bimodal effects of smoking on the brains of different tobacco smokers. Clinical Pharmacology & Therapeutics (2005) 77, P67–P67; doi: 10.1016/j.clpt.2004.12.147