ISSN:
1573-2657
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary The effects of purified ruthenium red (RR6+) on action potentials, resting potentials, twitches, tetani and potassium contractures in fibre bundles dissected from frog leg muscles were compared to the effects of supranormal concentrations of Ca2+. The effects of RR6+ include a shift of action potential threshold and reduction in rates of depolarization, repolarization and conduction velocity. Resting potentials and action potential overshoots are unaffected by RR6+ in concentrations of 10 µm or less. Higher RR6+ concentrations cause membrane depolarization. Low concentrations of RR6+ cause twitch potentiation but do not affect tetanus tension. Unlike Ca2+, RR6+ has no effect on the mechanical activation curve. However, crude preparations of RR6+ contain an unidentified contaminant which does shift the mechanical activation curve to the right, i.e. it increases mechanical threshold. RR6+ itself appears to be largely excluded from the t-system.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00818258
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