Isolated paced guinea pig left atrium: a new ouabain-induced arrhythmia model
Thomas, G.P.; Varma, R.K.
Methods and Findings in Experimental and Clinical Pharmacology 13(7): 459-462
1991
ISSN/ISBN: 0379-0355 PMID: 1784143 Document Number: 375241
Ouabain (1.0 x 10(-6) M) produced a uniform, consistent and reproducible arrhythmia on paced guinea pig left atrium bathed in Ringer-Locke solution. A second spell of arrhythmia of similar intensity and pattern, which had the same latency to onset, was reproduced 60 min after the first spell of arrhythmia. Lignocaine (3.46 x 10(-5) M) and propranolol (1.69 x 10(-5) M) gave full protection against the second spell of arrhythmia, whereas lower doses of these drugs were able to delay the onset and reduce the duration. Clonidine (3.75 x 10(-5) M), however, was found to be ineffective. This model can be used for the detection and assessment of directly acting antiarrhythmics in very low concentrations, since this is a sensitive and reliable method.