title: Effect of benzodiazepine hypnotic triazolam on relationship of blood pressure and Paco2 to cerebral blood flow during human non-rapid eye movement sleep.
abstract: 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.
authors.affiliation: Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto, Japan. CYI01752@nifty.com
authors.forename: Masahiko
authors.initials: M
authors.lastname: Hiroki
authors.forename: Naofumi
authors.initials: N
authors.lastname: Kajimura
authors.forename: Takeshi
authors.initials: T
authors.lastname: Uema
authors.forename: Kenichi
authors.initials: K
authors.lastname: Ogawa
authors.forename: Masami
authors.initials: M
authors.lastname: Nishikawa
authors.forename: Masaaki
authors.initials: M
authors.lastname: Kato
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Watanabe
authors.forename: Toru
authors.initials: T
authors.lastname: Nakajima
authors.forename: Harumasa
authors.initials: H
authors.lastname: Takano
authors.forename: Etsuko
authors.initials: E
authors.lastname: Imabayashi
authors.forename: Takashi
authors.initials: T
authors.lastname: Ohnishi
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Takayama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Matsuda
authors.forename: Makoto
authors.initials: M
authors.lastname: Uchiyama
authors.forename: Masako
authors.initials: M
authors.lastname: Okawa
authors.forename: Kiyohisa
authors.initials: K
authors.lastname: Takahashi
authors.forename: Hidenao
authors.initials: H
authors.lastname: Fukuyama
mesh_terms: D000328:Adult; D001785:Blood Gas Monitoring, Transcutaneous; D001794:Blood Pressure / Q000187:drug effects* / Q000502:physiology; D001921:Brain / Q000000981:diagnostic imaging; D002245:Carbon Dioxide / Q000097:blood*; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D018592:Cross-Over Studies; D005133:Eye Movements / Q000502:physiology; D005625:Frontal Lobe / Q000098:blood supply; D006801:Humans; D006993:Hypnotics and Sedatives / Q000494:pharmacology*; D008297:Male; D009778:Occipital Lobe / Q000098:blood supply; D010313:Partial Pressure; D049268:Positron-Emission Tomography; D012039:Regional Blood Flow / Q000187:drug effects; D012890:Sleep / Q000187:drug effects / Q000502:physiology*; D012894:Sleep Stages / Q000187:drug effects / Q000502:physiology; D014229:Triazolam / Q000494:pharmacology*
chemical_list: D006993:Hypnotics and Sedatives; D002245:Carbon Dioxide; D014229:Triazolam