The myocardial effects of fenoterol, isoprenaline and salbutamol in normoxic and hypoxic sheep.

摘要: Abstract Three groups, each of four sheep, were randomly allocated under blinded conditions to receive the beta-adrenoceptor agonists, salbutamol, fenoterol or isoprenaline, in doses 0.5, 2, 8, 32 and 128 micrograms/kg intravenously at 15-minute intervals. A separate group animals received equal volumes saline. Heart rate was recorded immediately prior drug administration serum potassium measured. Three 4 days later experiment repeated during induced systemic hypoxia then necropsied. All agonists produced significant increases heart rate. During hypoxia, lower rates than normoxic experiments. Under all beta-agonists hypokalaemia. Sterile saline had no effect on either levels. At necropsy, myocardial lesions found receiving three beta-agonists. Subendocardial haemorrhage consistently seen fenoterol. Multifocal myonecrosis 3-4 duration present left ventricle fenoterol, two isoprenaline salbutamol. The most severe papillary muscle visible grossly one animal given isoprenaline. No control animals.