title: Effect of change in intrathoracic pressure on thermoregulatory responses during -6 degree head-down bed rest.
abstract: We investigated the effect of change in intrathoracic pressure by total body negative pressure (TBNP) or positive pressure (TBPP) on thermoregulatory responses during -6 degree head-down bed rest (HDBR). Eight healthy male subjects participated to three of the following interventions in a randomised sequence: 1) HDBR, 2) HDBR with TBNP of -15 cmH2O, 3) HDBR with TBPP of +15 cmH2O. A rapid decrease of cutaneous blood flow occurred after the start of TBNP. In contrast, cutaneous blood flow increased slightly at TBPP. Sweat rate decreased immediately after the start of TBNP. Immediately after the TBPP was started, tympanic temperature greatly decreased. It is concluded that combination of HDBR and intrathoracic pressure changes thermoregulatory responses through the cardiopulmonary baroreceptor to reduce the wall stretch.
authors: Department of Physiology School of Medicine, Aichi Medical University, 21 Karimata, Yazako, Nagakute, Aichi, 480-1195, Japan. nao2460@aichi-med-u.ac.jp
authors: Naoki
authors: N
authors: Nishimura
authors: Luis
authors: L
authors: Beck
authors: Peter
authors: P
authors: Gauger
authors: Satoshi
authors: S
authors: Iwase
authors: Junichi
authors: J
authors: Sugenoya
mesh_terms: D000328:Adult; D017704:Baroreflex; D001510:Bed Rest; D001831:Body Temperature; D001833:Body Temperature Regulation; D003664:Decompression; D018475:Head-Down Tilt; D006801:Humans; D008297:Male; D011312:Pressure; D012039:Regional Blood Flow; D012867:Skin / Q000098:blood supply*; D013546:Sweating