Effect of verapamil on Ca2+ influx to rat phrenic nerve-diaphragm preparation.
The effect of verapamil on contractility and on influx of calcium (Ca2+) to the rat phrenic nerve-hemidiaphragm preparation was studied in vitro, at rest and during electrical stimulation at 0.2-100 Hz. Calcium content of the bathing solution was measured using the Technicon method (SMAC, Sequential Multiple Analyser/Computer). The results showed that verapamil (a) reduced the twitch and tetanic contractions in a non-competitive manner, and (b) reduced the influx of Ca2+ to the rat hemidiaphragm preparation. Greater reductions occurred as the rate of stimulation increased.
Wali
F A
FA
Anaesthetics Unit, London Hospital Medical College, Whitechapel.
Suer
A H
AH
D000818:Animals; D002118:Calcium / Q000493:pharmacokinetics*; D003864:Depression, Chemical; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009469:Neuromuscular Junction / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D014700:Verapamil / Q000494:pharmacology*
D014700:Verapamil; D002118:Calcium