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This Article Full Text Full Text (PDF) Supplemental Tables and Figures All Versions of this Article: 95/4/2293    most recent 00114.2005v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Hiroki, M. Articles by Fukuyama, H. Search for Related Content PubMed PubMed Citation Articles by Hiroki, M. Articles by Fukuyama, H.

Effect of Benzodiazepine Hypnotic Triazolam on Relationship of Blood Pressure and PaCO₂ to Cerebral Blood Flow During Human Non-Rapid Eye Movement Sleep

¹Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto; ²Departments of Psychiatry, ³Anesthesiology, and ⁴Radiology, National Center Hospital for Mental, Nervous, and Muscular Disorders, National Center of Neurology and Psychiatry (NCNP), Tokyo; ⁵Department of Psychiatry, Osaka Prefectural General Hospital, Osaka,; ⁶Department of Psychiatry, Teikyo University School of Medicine, Kanagawa; ⁷Department of Psychiatry, National Institute of Mental Health, NCNP, Chiba; and ⁸Department of Psychiatry, Shiga University of Medical Science, Shiga, Japan

Submitted 1 February 2005; accepted in final form 3 October 2005

We sought to clarify the effect of short-acting benzodiazepine hypnotic on the relationship of arterial blood pressure and arterial partial pressure of carbon dioxide (PaCO₂) to regional cerebral blood flow (rCBF) during human non-rapid-eye-movement (non-REM) sleep. Nine young normal volunteers were treated in a randomized, crossover design with triazolam or placebo and underwent positron emission tomography at night. During wakefulness and stage 2 and slow wave (stages 3 and 4) sleep, we measured mean arterial blood pressure (MAP), PaCO₂, and absolute CBF. With triazolam compared to placebo, MAP reduced gradually. During stage 2 sleep, PaCO₂ increased and whole-brain mean CBF decreased. With triazolam, relative rCBF of the left orbital basal forebrain decreased more during stage 2 than slow wave sleep, whereas absolute CBF of the occipital cortex and cerebral white matter remained constant. During triazolam-induced stage 2 sleep, absolute CBF of the cerebral white matter correlated more strongly to both MAP and PaCO₂ than during placebo sleep and also correlated more strongly to both MAP and PaCO₂ than absolute CBF of the occipital cortex. In the frontal white matter, during triazolam-induced stage 2 sleep compared to wakefulness, absolute CBF was significantly better correlated to MAP, but not to PaCO₂. During triazolam-induced stage 2, the cerebral white matter may receive a modulated CBF regulation having the strengthened relationship of PaCO₂ to CBF and, more locally, the frontal white matter may depend precariously on CBF regulation.