Dantrolene, like fatigue, has a length‐dependent effect on submaximal force–length relationships of rat gastrocnemius muscle

Abstract

This study demonstrates that there is a length dependence of force depression associated with decreased Ca2+ release due to dantrolene treatment; therefore, if fatigue is due to decreased Ca2+ release, then additional length-dependent mechanisms are not required to explain the reported length dependence of force depression.

Can muscle fatigue in women be influenced by knee extension tasks in different ranges of motion?

“…Thus, the force reduction due to the decrease of Ca 2+ release in fatigue conditions would be minimized when the muscle is demanded to contract at a bigger length than at a smaller one. This suggestion is supported by the findings by MacNaughton et al [27], who demonstrated a greater decrease of active force at a small muscle length in comparison with optimal muscle length. Moreover, at a bigger muscle length, less overlapping of actin and myosin is expected to occur than at a smaller muscle length [10].…”

Pattern of summation with fatigue and inhibition of calcium release in rat muscle

“…In some cases, Ptw was estimated from the first bump of the incompletely fused tetanic contraction at 50 H Z . This frequency of stimulation is commonly used to elicit fatigue in mammalian muscles 21, 26…”

“…This frequency of stimulation is commonly used to elicit fatigue in mammalian muscles. 21,26 Experiment 1. In the first experiment, the consequences of intermittent repetitive stimulation on summation were evaluated (n ¼ 8).…”

“…In this regard, comparisons between changes in summation during fatigue and recovery with corresponding changes in the presence of dantrolene, a drug that inhibits Ca 2þ release through RyR, 17,18 may be informative. Dantrolene has been used successfully in studies comparing contractile changes with Ca 2þ inhibition and those associated with low-frequency fatigue, [19][20][21] but not in association with summation.…”

Elevation of liver function tests in severe anorexianervosa

“…In this regard, comparisons between changes in summation during fatigue and recovery with corresponding changes in the presence of dantrolene, a drug that inhibits Ca 2+ release through RyR,17, 18 may be informative. Dantrolene has been used successfully in studies comparing contractile changes with Ca 2+ inhibition and those associated with low‐frequency fatigue,19–21 but not in association with summation.…”