The effect of modification of sympathetic activity on responses to ligation of a coronary artery in the conscious rat.
1 Ligation of a coronary artery was performed in conscious rats whose sympathetic system activity had been altered by various treatments. 2 beta-Adrenoceptor blockade with acute (0.2 mg kg-1 plus 0.1 micrograms kg-1 min-1) or chronic (50-60 mg kg-1 daily for 12 days) propranolol treatment had little effect on arrhythmias, or other responses to ligation. 3 Abrupt withdrawal of chronic propranolol two days before ligation was also without effect. 4 Reduction of sympathetic activity acutely with labetalol (5 mg kg-1), or chronically with adrenomedullectomy and 6-hydroxydopamine treatment, accentuated the adverse effects of ligation. 5 The results of this study suggest that, while activity of the sympathetic system is not detrimental during ligation in the conscious rat, it may be important for survival.
D000315:Adrenalectomy; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D001145:Arrhythmias, Cardiac / Q000503:physiopathology; D001794:Blood Pressure / Q000187:drug effects; D003331:Coronary Vessels / Q000502:physiology*; D004562:Electrocardiography; D006339:Heart Rate / Q000187:drug effects; D006892:Hydroxydopamines / Q000494:pharmacology; D008026:Ligation; D009203:Myocardial Infarction / Q000503:physiopathology; D016627:Oxidopamine; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013563:Sympathectomy, Chemical; D013564:Sympathetic Nervous System / Q000502:physiology*
D000319:Adrenergic beta-Antagonists; D006892:Hydroxydopamines; D016627:Oxidopamine; D011433:Propranolol