Effect of body temperature during exercise on skeletal muscle cytochrome c oxidase content

• Published in: Journal of applied physiology (1985) 2002-08, Vol.93 (2), p.526-530
• Main Authors: Mitchell, Christopher R, Harris, M. Brennan, Cordaro, Anthony R, Starnes, Joseph W
• Format: Article
• Language: English
• Subjects: Anatomy & physiology; Animals; Biological and medical sciences; Body Temperature - physiology; Cold Temperature; Electron Transport Complex IV - metabolism; Exercise; Fundamental and applied biological sciences. Psychology; HSP70 Heat-Shock Proteins - metabolism; Male; Membrane Proteins - metabolism; Mitochondria - enzymology; Muscle, Skeletal - physiology; Physical Endurance - physiology; Physical Exertion - physiology; Proteins; Rats; Rats, Sprague-Dawley; Rodents; Striated muscle. Tendons; Temperature; Vertebrates: osteoarticular system, musculoskeletal system
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/japplphysiol.00536.2001

1  Department of Kinesiology, Southwestern University, Georgetown 78626; and 2  Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, Texas 78712 This study determined the role of body temperature during exercise on cytochrome- c oxidase (CytOx) activity, a marker of mitochondrial content, and mitochondrial heat shock protein 70   (mtHSP70), which is required for import of nuclear-coded preproteins. Male, 10-wk-old, Sprague-Dawley rats exercised identically for 9 wk in ambient temperatures of 23°C ( n  = 10), 8°C with wetted fur ( n  = 8), and 4°C with wetted fur and fan ( n  = 7). These conditions maintained exercising core temperature (T c ) at 40.4, 39.2, or 38.0°C (resting temperature), respectively. During weeks 3-9 , exercisers ran 5 days/wk up a 6% grade at 20 m/min for 60 min. Animals were housed at 23°C. Gastrocnemius CytOx activity in T c =38.0°C (83.5 ± 5.5 µatoms O · min 1 · g wet wt 1 ) was greater than all other groups ( P