Dantrolene effects on neuromuscular function in cat soleus muscle

• Published in: European journal of pharmacology Vol. 32; no. 2; p. 267
• Main Author: Lowndes, H E
• Format: Journal Article
• Language: English
• Published: Netherlands 01-01-1975
• Subjects: Animals; Blood Pressure; Cats; Dantrolene - pharmacology; Electric Stimulation; Female; Hydantoins - pharmacology; In Vitro Techniques; Male; Motor Neurons - drug effects; Muscle Contraction - drug effects; Muscles - physiology; Nerve Endings - drug effects; Neuromuscular Junction - drug effects
• ISSN: 0014-2999
• DOI: 10.1016/0014-2999(75)90292-7

Dantrolene sodium (DS) was investigated for its effects on cat soleus muscle contractile properties and motor nerve terminal activity in particular. DS, 0.1-1.5 mg/kg i.v., caused a dose-dependent depression of indirectly elicited contractile strength which was more pronounced at lower frequencies of stimulation. Maximum tetanic strength at frequencies of 10-400 Hz was depressed to a lesser degree than contractile responses evoked by lower frequencies of stimulation; the twitch/tetanus contraction ratios were reduced with increasing dose, primarily because of diminished twitch. DS was without effect on motor nerve terminals as evidenced by normal post-tetanic repetition in the nerves following DS administration. Post-tetanic potentiation became relatively larger in amplitude as contractile strength was diminished. These data suggest that DS depresses neuromuscular function at a site other than the neural apparatus at the neuromuscular junction.