PMID: 8595616Nov 1, 1995Paper

Protection by cimetidine, but not ranitidine, implies that H2 receptors do not mediate arrhythmogenesis in a rat model of regional ischaemia and reperfusion in vitro

Cardiovascular Research
M M Banning, M J Curtis

Abstract

Evidence suggests that histamine may function as one of many endogenous biochemical mediators of ischaemia- and reperfusion-induced ventricular fibrillation (VF). The H2 receptor subtype has been hypothesised to mediate this action. Our objective was to test this hypothesis. The hypothesis predicts that H2 antagonists should prevent VF. We tested this by evoking ischaemia- and reperfusion-induced VF using the isolated perfused rat heart (Langendorff preparation) and performing concentration-response studies with two H2 antagonists, cimetidine and ranitidine. Continuous perfusion with cimetidine at the highest concentration (10 microM) reduced the incidence of ischaemia-induced VF from 57% in controls to 8% (P < 0.05) and the incidence of reperfusion-induced VF from 78 to 38% (P < 0.05). Surprisingly, the incidences of ischaemia- and reperfusion-induced arrhythmias were not reduced by ranitidine over an equivalent concentration range (0.1-10 microM). Electrocardiographic (ECG) variables (PR and QT interval) were not altered by cimetidine or ranitidine at any concentration, suggesting that neither drug produced direct electrophysiological actions on fast inward sodium, L-type calcium or potassium currents (blockade of which would...Continue Reading

Citations

Jan 22, 2004·Proceedings of the National Academy of Sciences of the United States of America·David J GranvilleRoberta A Gottlieb
Aug 28, 2014·Pharmacology & Therapeutics·Gabrielle B Adkins, Michael J Curtis
Mar 26, 1998·Journal of Cardiovascular Pharmacology·R A HumphreysJ R Parratt

❮ Previous
Next ❯

Related Concepts

Related Feeds

Anti-Arrhythmic Drug Therapies

Anti-arrhythmic drugs are used to prevent abnormal heart rhythms. These medications are used in conditions including, ventricular tachycardia, ventricular fibrillation and atrial fibrillation. Discover the latest research on anti-arrhythmic drug therapies here.

Antiarrhythmic Agents: Mechanisms of Action

Understanding the mechanism of action of antiarrhythmic agents is essential in developing new medications as treatment of cardiac arrhythmias is currently limited by the reduced availability of safe and effective drugs. Discover the latest research on Antiarrhythmic Agents: Mechanism of Action here.

Arrhythmia

Arrhythmias are abnormalities in heart rhythms, which can be either too fast or too slow. They can result from abnormalities of the initiation of an impulse or impulse conduction or a combination of both. Here is the latest research on arrhythmias.

Atrial Fibrillation

Atrial fibrillation is a common arrhythmia that is associated with substantial morbidity and mortality, particularly due to stroke and thromboembolism. Here is the latest research.