ACTIONS OF PROSTAGLANDIN-I2 AND PROSTAGLANDIN-E2 ON ARRHYTHMIAS PRODUCED BY CORONARY-OCCLUSION IN THE RAT AND DOG

Prostaglandins E2 and I2 were compared with known antiarrhythmics for their actions against arrhythmias produced by occlusion of the left anterior descending coronary artery in the anaesthetised rat while PGI2 was also examined in the dog. PGI2 in the dog suppressed early arrhythmias produced during occlusion but did not influence those produced by occlusion-release or those occurring 24 hours after a permanent occlusion; none of the A,B,C or D series prostaglandins tested markedly reduced 24 hour arrhythmias. In the rat PGE2 was antiarrhythmic against early occlusion arrhythmias (30 minutes occlusion) in a dose related manner (infusions of 1-4 μg/kg/min) whereas PGI2 infusions potentiated the arrhythmogenic effect of occlusion. PGE2 was as effective an antiarrhythmic as 10mg/kg Org. 6001 which was more effective in this test situation than d1-propranolol. No obvious mechanisms for the actions of PGE2 or PGI2 were apparent although both agents lowered blood pressure and reduced the size of the occluded zone produced by ligation. © 1979.