| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Department of Physiology, University of Kentucky, Lexington, KY, USA
* To whom correspondence should be addressed. E-mail: michael.reid{at}uky.edu.
Free radicals are produced continuously by skeletal muscle fibers. Extracellular release of reactive oxygen species (ROS) and nitric oxide (NO) derivatives has been demonstrated but little is known about intracellular oxidant regulation. We used a fluorescent oxidant probe, 2',7'-dichlorofluorescin (DCFH) to assess net oxidant activity in passive muscle fiber bundles isolated from mouse diaphragm and studied in vitro. We tested three hypotheses: 1) Net oxidant activity is decreased by muscle cooling. 2) CO2 exposure depresses intracellular oxidant activity. 3.) Muscle-derived ROS and NO both contribute to overall oxidant activity. Our results indicate that DCFH oxidation was diminished by cooling muscle fibers from 37°C to 23°C (P<0.001). The rate of DCFH oxidation correlated positively with CO2 exposure (0-10%; P<0.05) and negatively with concurrent changes in pH (7.0-8.5; P<0.05). Separate exposures to anti-ROS enzymes (SOD 1 kU/ml, catalase 1 kU/ml), a glutathione peroxidase mimetic (ebselen 30 µM), NO synthase inhibitors (L-NAME 1 mM, L-NMMA 1 mM), or an NO scavenger (hemoglobin 1 µM) each inhibited DCFH oxidation (P<0.05). Oxidation was increased by hydrogen peroxide 100 µM, an NO donor (NOC-22 400 µM), or the substrate for NO synthase (L-arginine 5 mM). We conclude that net oxidant activity in resting muscle fibers is: 1) decreased at subphysiological temperatures, 2) increased by CO2 exposure, and 3) influenced by muscle-derived ROS and NO derivatives to similar degrees.
This article has been cited by other articles:
|
|
 |
|
  N. P. Whitehead, C. Pham, O. L. Gervasio, and D. G. Allen N-Acetylcysteine ameliorates skeletal muscle pathophysiology in mdx mice J. Physiol., April 1, 2008; 586(7): 2003 - 2014. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. F. Ferreira and M. B. Reid Muscle-derived ROS and thiol regulation in muscle fatigue J Appl Physiol, March 1, 2008; 104(3): 853 - 860. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. J. Hardin, K. S. Campbell, J. D. Smith, S. Arbogast, J. Smith, J. S. Moylan, and M. B. Reid TNF-{alpha} acts via TNFR1 and muscle-derived oxidants to depress myofibrillar force in murine skeletal muscle J Appl Physiol, March 1, 2008; 104(3): 694 - 699. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. G. Allen, G. D. Lamb, and H. Westerblad Skeletal Muscle Fatigue: Cellular Mechanisms Physiol Rev, January 1, 2008; 88(1): 287 - 332. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. van der Poel and D. G. Stephenson Effects of elevated physiological temperatures on sarcoplasmic reticulum function in mechanically skinned muscle fibers of the rat Am J Physiol Cell Physiol, July 1, 2007; 293(1): C133 - C141. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Pye, J. Palomero, T. Kabayo, and M. J. Jackson Real-time measurement of nitric oxide in single mature mouse skeletal muscle fibres during contractions J. Physiol., May 15, 2007; 581(1): 309 - 318. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. van der Poel, J. N. Edwards, W. A. Macdonald, and D. G. Stephenson Mitochondrial superoxide production in skeletal muscle fibers of the rat and decreased fiber excitability Am J Physiol Cell Physiol, April 1, 2007; 292(4): C1353 - C1360. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Arbogast, J. Smith, Y. Matuszczak, B. J. Hardin, J. S. Moylan, J. D. Smith, J. Ware, A. R. Kennedy, and M. B. Reid Bowman-Birk inhibitor concentrate prevents atrophy, weakness, and oxidative stress in soleus muscle of hindlimb-unloaded mice J Appl Physiol, March 1, 2007; 102(3): 956 - 964. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. J. Falk, K. C. DeRuisseau, D. L. Van Gammeren, M. A. Deering, A. N. Kavazis, and S. K. Powers Mechanical ventilation promotes redox status alterations in the diaphragm J Appl Physiol, October 1, 2006; 101(4): 1017 - 1024. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. C. Gong, S. Arbogast, Z. Guo, J. Mathenia, W. Su, and M. B. Reid Calcium-independent phospholipase A2 modulates cytosolic oxidant activity and contractile function in murine skeletal muscle cells J Appl Physiol, February 1, 2006; 100(2): 399 - 405. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. R Moopanar and D. G Allen Reactive oxygen species reduce myofibrillar Ca2+ sensitivity in fatiguing mouse skeletal muscle at 37{degrees}C J. Physiol., April 1, 2005; 564(1): 189 - 199. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
