TY - JOUR
TI - Heterogeneous sensitivity of cerebral and muscle tissues to acute normobaric hyperoxia at rest
AU - Keramidas, M.E.
AU - Kounalakis, S.N.
AU - Geladas, N.D.
AU - Eiken, O.
AU - Mekjavic, I.B.
JO - Microvascular Research
PY - 2012
VL - 84
TODO - 2
SP - 205-210
PB - 
SN - 0026-2862, 1095-9319
TODO - 10.1016/j.mvr.2012.05.007
TODO - deoxyhemoglobin;  oxygen;  oxyhemoglobin, adult;  arterial oxygen tension;  article;  brain;  breathing muscle;  frontal cortex;  human;  human experiment;  hyperoxia;  intercostal muscle;  leg muscle;  male;  near infrared spectroscopy;  normal human;  priority journal;  tissue oxygenation;  vastus lateralis muscle, Acute Disease;  Adult;  Biological Markers;  Brain;  Cerebral Cortex;  Cross-Over Studies;  Hemodynamics;  Hemoglobins;  Humans;  Hyperoxia;  Intercostal Muscles;  Male;  Oxygen;  Oxyhemoglobins;  Quadriceps Muscle;  Rest;  Single-Blind Method;  Spectroscopy, Near-Infrared;  Time Factors;  Young Adult
TODO - The purpose was to investigate the effects of acute normobaric hyperoxia at rest on cerebral, respiratory and leg muscle oxygenation. Ten healthy men were studied twice in a single-blinded counterbalanced crossover study protocol. On one occasion they breathed air and on the other 100% normobaric O2 for a 2-hour time period. Oxygenated (δ[O2Hb]), deoxygenated (δ[HHb]) and total (δ[tHb]) hemoglobin in the cerebral frontal cortex, and in the intercostal and vastus lateralis muscles were simultaneously monitored with near-infrared spectroscopy. The hyperoxic stimulus promptly increased δ[O2Hb] (~2μM) and decreased δ[HHb] (~3.6μM) in the frontal cortex. These cerebral responses were directly and fully countered by resumption of normoxic air breathing. In contrast, δ[HHb] significantly decreased due to the acute hyperoxic stimulus in both intercostal and vastus lateralis muscles. The temporal changes in muscle oxygenation were slower compared to those in the cerebral area; and they only partially recovered during the 15-min normoxic-recovery period. Acute supplementation of normobaric O2 at rest influences cerebral, leg and respiratory muscle oxygenation of healthy individuals, but not in the same manner. Namely, the frontal cortex seems to be more sensitive to hyperoxia than are the skeletal muscle regions. © 2012 Elsevier Inc.
ER -