Bradykinin is a mediator, but unlikely a trigger, of antiarrhythmic effects of ischemic preconditioning.

Abstract

OBJECTIVE:

Brief reversible ischemic episodes (ischemic preconditioning, IPC) protect the heart against arrhythmias during a subsequent prolonged low-flow ischemia. We have recently shown that this protection involves release of bradykinin, activation of bradykinin B2 receptors followed by opening of sarcolemmal, but not mitochondrial ATP-sensitive K+ channels. The goal of this study was to clarify a trigger and/or mediator role of bradykinin in the antiarrhythmic effects of IPC during low-flow ischemia.

METHODS:

Isolated perfused rat hearts underwent 60 minutes of low-flow ischemia induced by reducing perfusion pressure followed by 60 minutes of reperfusion. Preconditioning was induced by 2 x 5 minutes episodes of zero-flow ischemia. In yet other groups, preconditioned or non-preconditioned hearts were treated either with bradykinin (10 nmol/L) or with HOE 140 (bradykinin B2 receptor antagonist, 100 nmol/L).

RESULTS:

IPC reduced the number of ventricular premature beats, as well as the incidence of ventricular tachycardia and of ventricular fibrillation during low-flow ischemia. In addition, this protection was abolished by HOE 140 given during low-flow ischemia. Pharmacological preconditioning using short bradykinin perfusion instead of IPC did not show antiarrhythmic effects. However, bradykinin administered during low-flow ischemia and reperfusion reduced the number of ventricular premature beats and the incidence of ventricular tachycardia and of ventricular fibrillation during low-flow ischemia.

CONCLUSION:

Bradykinin is a mediator, but unlikely a trigger, of antiarrhythmic effects of IPC during low-flow ischemia.

• Authors: Sergey V Driamov, Mohamed Bellahcene, Silvia Butz, Peter T Buser, Christian E Zaugg
• Journal: Journal of cardiovascular electrophysiology (J Cardiovasc Electrophysiol) Vol. 18 Issue 1 Pg. 93-9 (Jan 2007) ISSN: 1540-8167 [Electronic] United States
• PMID: 17229306 (Publication Type: Journal Article)

Chemical References

• Bradykinin Receptor Antagonists
• icatibant
• Bradykinin

Topics

• Animals
• Bradykinin (analogs & derivatives, drug effects, metabolism, pharmacology)
• Bradykinin Receptor Antagonists
• Disease Models, Animal
• Disease Progression
• Electrocardiography
• Heart Rate (physiology)
• Heart Ventricles (drug effects, metabolism, physiopathology)
• Ischemic Preconditioning, Myocardial (methods)
• Male
• Pilot Projects
• Prognosis
• Rats
• Rats, Sprague-Dawley
• Tachycardia, Ventricular (etiology, metabolism, prevention & control)
• Ventricular Fibrillation (etiology, metabolism, prevention & control)