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Failure of nitric oxide donors to alter arrhythmias induced by acute myocardial ischaemia or reperfusion in anaesthetized rats
Author(s) -
Barnes Christopher S.,
Coker Susan J.
Publication year - 1995
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1995.tb13233.x
Subject(s) - sodium nitroprusside , medicine , ventricular fibrillation , cardiology , nitric oxide , isosorbide dinitrate , anesthesia , ventricular tachycardia , coronary occlusion , ischemia , tachycardia
1 The aim of the present studies was to examine the effects of nitric oxide donors on arrhythmias induced by coronary artery occlusion and reperfusion, and on cardiac cyclic nucleotides. Experiments were performed in pentobarbitone‐anaesthetized rats prepared for occlusion of the left coronary artery. 2 Sodium nitroprusside (0.1, 0.3 and 1 μg kg −1 min −1 ) had no significant effects on the incidence of ventricular tachycardia, total ventricular fibrillation or the mortality resulting from 25 min of acute myocardial ischaemia when compared with values in controls. In addition, there was no alteration in the number of ventricular premature beats that occurred in survivors. 3 3‐Morpholinosydnonimine‐N‐ethylcarbamide (SIN‐1, 10, 20 and 40 μg kg −1 min −1 ) caused marked hypotension but did not alter the incidence or severity of ischaemia‐induced arrhythmias. In rats subject to abrupt reperfusion after 5 min of myocardial ischaemia, lower doses of SIN‐1 (1, 3 and 10 μg kg −1 min −1 ) still caused significant reductions in systolic and diastolic blood pressure but were devoid of antiarrhythmic activity. 4 In separate experiments in sham‐operated rats, sodium nitroprusside (1 μg kg −1 min −1 ), isosorbide dinitrate (30 and 60 μg kg −1 min −1 ) and SIN‐1 (20 and 40 μg kg −1 min −1 ) had no significant effects on cardiac cyclic GMP content. 5 These results indicate that nitric oxide donors do not alter arrhythmias induced by acute coronary artery occlusion or reperfusion in anaesthetized rats. Although increases in total cardiac cyclic GMP could not be detected, the results suggest that, at least in the rat, cyclic GMP does not influence these arrhythmias.