Influence of extracellular calcium in the effects of dibekacin and diltiazem on indirectly elicited tetanic responses in the rat phrenic-hemidiaphragm preparation.
1. Dibekacin (70 microM-3 mM) produced a decrease of peak tetanic tension in a concentration-dependent manner and this effect was dependent on extracellular calcium (0.3-2.5 mM Ca2+). Only minimal fade was observed and it was not related with extracellular calcium concentrations. 2. Diltiazem (30-300 microM) decreased peak tetanic tension and produced tetanic fade. Both effects were independent of extracellular calcium, although a significant potentiation was observed at 0.3 mM calcium. 3. It is concluded that tetanic parameters are related differently to extracellular calcium.
Baños
J E
JE
Departament de Farmacologia i Psiquiatria, Universitat Autònoma de Barcelona, Spain.
Bosch
F
F
Badia
A
A
D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D003964:Diaphragm / Q000187:drug effects; D003982:Dibekacin / Q000494:pharmacology*; D004110:Diltiazem / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects; D066298:In Vitro Techniques; D007612:Kanamycin / Q000031:analogs & derivatives*; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000166:cytology / Q000187:drug effects; D009469:Neuromuscular Junction / Q000187:drug effects; D010791:Phrenic Nerve / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D012132:Respiratory Muscles / Q000187:drug effects*
D003982:Dibekacin; D007612:Kanamycin; D004110:Diltiazem; D002118:Calcium