HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Bruton, J D Articles by Westerblad, H Search for Related Content PubMed PubMed Citation Articles by Bruton, J D Articles by Westerblad, H

Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.

1. Single skeletal muscle fibres of Xenopus laevis were used to investigate the involvement of a mechano-sensitive link in excitation-contraction coupling (EC coupling). 2. Fibres were stimulated by intermittent tetani until tension fell to about 40% of its initial level. Fibres were then stressed either by briefly stretching the fibres to 120% of their resting length or by exposing them to hypotonic Ringer solution ([NaCl] reduced to 80%) for 5 min. 3. In six of thirty-five stretched fibres and in all fourteen fibres exposed to hypotonic solution, a long-lasting depression of tension ensued. Tetanic tension then recovered slowly, often taking more than 10 h to return to its initial level. 4. During the period of minimal tension production, 12 mM caffeine induced a maximum contracture; 190 mM K+ induced a contracture larger than previous or subsequent tetani, and perchlorate (1 mM) slightly augmented tetanic tension. 5. Neither protease inhibitors nor a protein synthesis inhibitor altered the long-lasting period of tension depression and slow recovery. A free-radical scavenger was also without effect. 6. It is concluded that there is a mechano-sensitive link involved in EC coupling which can be damaged easily in fatigued muscle fibres.

This article has been cited by other articles:

				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]

				D. G. Allen, G. D. Lamb, and H. Westerblad Impaired calcium release during fatigue J Appl Physiol, January 1, 2008; 104(1): 296 - 305. [Abstract] [Full Text] [PDF]