| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5; and 2 Department of Molecular Medicine, Chiba University Graduate School of Medicine, Chiba 260-8670, Japan
The objective of this study was to determine how an ATP-sensitive K+ (KATP) channel deficiency affects the contractile and fatigue characteristics of extensor digitorum longus (EDL) and soleus muscle of 2- to 3-mo-old and 1-yr-old mice. KATP channel-deficient mice were obtained by disrupting the Kir6.2 gene that encodes for the protein forming the pore of the channel. At 2-3 mo of age, the force-frequency curve, the twitch, and the tetanic force of EDL and soleus muscle of KATP channel-deficient mice were not significantly different from those in wild-type mice. However, the tetanic force and maximum rate of force development decreased with aging to a greater extent in EDL and soleus muscle of KATP channel-deficient mice (24-40%) than in muscle of wild-type mice (7-17%). During fatigue, the KATP channel deficiency had no effect on the decrease in tetanic force in EDL and soleus muscle, whereas it caused a significantly greater increase in resting tension when compared with muscle of wild-type mice. The recovery of tetanic force after fatigue was not affected by the deficiency in 2- to 3-mo-old mice, whereas in 1-yr-old mice, force recovery was significantly less in muscle of KATP channel-deficient than wild-type mice. It is suggested that the major function of the KATP channel during fatigue is to reduce the development of a resting tension and not to contribute to the decrease in force. It is also suggested that the KATP channel plays an important role in protecting muscle function in older mice.
Kir6.2; knockout; mouse; twitch; tetanus; force-frequency curve
This article has been cited by other articles:
|
|
 |
|
  T. J. Craig, F. M. Ashcroft, and P. Proks How ATP Inhibits the Open KATP Channel J. Gen. Physiol., July 1, 2008; 132(1): 131 - 144. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Cifelli, F. Bourassa, L. Gariepy, K. Banas, M. Benkhalti, and J.-M. Renaud KATP channel deficiency in mouse flexor digitorum brevis causes fibre damage and impairs Ca2+ release and force development during fatigue in vitro J. Physiol., July 15, 2007; 582(2): 843 - 857. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Kristensen, T. Hansen, and C. Juel Membrane proteins involved in potassium shifts during muscle activity and fatigue Am J Physiol Regulatory Integrative Comp Physiol, March 1, 2006; 290(3): R766 - R772. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Thabet, T. Miki, S. Seino, and J.-M. Renaud Treadmill running causes significant fiber damage in skeletal muscle of KATP channel-deficient mice Physiol Genomics, July 14, 2005; 22(2): 204 - 212. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Minami, T. Miki, T. Kadowaki, and S. Seino Roles of ATP-Sensitive K+ Channels as Metabolic Sensors: Studies of Kir6.x Null Mice Diabetes, December 1, 2004; 53(suppl_3): S176 - S180. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. P. Flagg, F. Charpentier, J. Manning-Fox, M. S. Remedi, D. Enkvetchakul, A. Lopatin, J. Koster, and C. Nichols Remodeling of excitation-contraction coupling in transgenic mice expressing ATP-insensitive sarcolemmal KATP channels Am J Physiol Heart Circ Physiol, April 1, 2004; 286(4): H1361 - H1369. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Kristensen and T. Hansen Statistical analyses of repeated measures in physiological research: a tutorial Advan Physiol Educ, March 1, 2004; 28(1): 2 - 14. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Seino and T. Miki Gene targeting approach to clarification of ion channel function: studies of Kir6.x null mice J. Physiol., January 15, 2004; 554(2): 295 - 300. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. Gong, D. Legault, T. Miki, S. Seino, and J. M. Renaud KATP channels depress force by reducing action potential amplitude in mouse EDL and soleus muscle Am J Physiol Cell Physiol, December 1, 2003; 285(6): C1464 - C1474. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. J. Nielsen, M. Kristensen, Y. Hellsten, J. Bangsbo, and C. Juel Localization and function of ATP-sensitive potassium channels in human skeletal muscle Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2003; 284(2): R558 - R563. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Miki, K. Minami, L. Zhang, M. Morita, T. Gonoi, T. Shiuchi, Y. Minokoshi, J.-M. Renaud, and S. Seino ATP-sensitive potassium channels participate in glucose uptake in skeletal muscle and adipose tissue Am J Physiol Endocrinol Metab, December 1, 2002; 283(6): E1178 - E1184. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. Matar, J. A. Lunde, B. J. Jasmin, and J.-M. Renaud Denervation enhances the physiological effects of the KATP channel during fatigue in EDL and soleus muscle Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2001; 281(1): R56 - R65. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
