title: Hyperbaric exposure with high oxygen concentration enhances oxidative capacity of neuromuscular units.
abstract: The effects of hyperbaric exposure with high oxygen concentration on spinal motoneurons and the skeletal muscle fibers that they innervate were investigated. Five-week-old male rats were exposed to a hyperbaric (1.25 atmospheric pressure) environment with a high oxygen concentration (35.0%) for 6h daily. The number, cell body size, and oxidative enzyme activity of motoneurons innervating the soleus and plantaris muscles were examined after 8 weeks of hyperbaric exposure. In addition, the fiber type distribution, cell size, and oxidative enzyme activity of the slow soleus and fast plantaris muscles were examined. The oxidative enzyme activity of alpha motoneurons innervating the soleus and plantaris muscles increased after hyperbaric exposure, irrespective of their cell body sizes. The percentage of high-oxidative fibers in the soleus and plantaris muscles increased after hyperbaric exposure. The oxidative enzyme activity of all types of fibers in the soleus and plantaris muscles increased after hyperbaric exposure. It is concluded that hyperbaric exposure with high oxygen concentration enhances the oxidative capacity of neuromuscular units.
authors.affiliation: Laboratory of Neurochemistry, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606-8501, Japan. ishihara@life.h.kyoto-u.ac.jp
authors.forename: Akihiko
authors.initials: A
authors.lastname: Ishihara
authors.forename: Fuminori
authors.initials: F
authors.lastname: Kawano
authors.forename: Tomonori
authors.initials: T
authors.lastname: Okiura
authors.forename: Fumiki
authors.initials: F
authors.lastname: Morimatsu
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Ohira
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D001274:Atmospheric Pressure; D008297:Male; D009046:Motor Neurons / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000294:innervation / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013116:Spinal Cord / Q000378:metabolism; D013385:Succinate Dehydrogenase / Q000378:metabolism
chemical_list: D013385:Succinate Dehydrogenase; D000251:Adenosine Triphosphatases; D010100:Oxygen