Experimental cardio-depressant effects of clonixin.
1. The cardiovascular effects of CLX were studied. 2. CLX induced hypotension, bradycardia, negative chronotropism and negative inotropism. 3. Electrophysiological studies showed a decrease of sinus venosus discharge frequency. The action potential configuration was changed: the overshoot amplitude and (dV/dt)max were reduced and duration increased. 4. CLX at higher concentrations displaced the maximum diastolic potential and phase 4 slow diastolic depolarization was lengthened. 5. The above findings could be explained by a depressant action of CLX on the electrical activity of the pacemaker cells, possibly by a modification of the slow calcium currents.
Bustamante
D
D
Departamento de Farmacologia, Facultad de Medicina, Universidad de Chile, Santiago.
Morales
M
M
Pelissier
T
T
Saavedra
H
H
Miranda
H F
HF
Paeile
C
C
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D000889:Anti-Arrhythmia Agents; D001001:Anura; D001794:Blood Pressure / Q000187:drug effects; D003002:Clonixin / Q000494:pharmacology*; D004594:Electrophysiology; D006339:Heart Rate / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D009539:Nicotinic Acids / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D015656:Respiratory Mechanics / Q000187:drug effects; D012849:Sinoatrial Node / Q000187:drug effects / Q000502:physiology
D000889:Anti-Arrhythmia Agents; D009539:Nicotinic Acids; D003002:Clonixin