A comparison of the cardiovascular actions of four adrenergic β-receptor blocking agents in resting, conscious dogs

摘要: Abstract The present study was undertaken to investigate the effect of blockade adrenergic β-receptors on resting hemodynamics in conscious dogs. Contrary findings anesthetized animals, which activity autonomic nervous system is markedly altered, propranolol and MJ 1999 had little heart rate, cardiac output, left ventricular work. These two drugs were also equipotent blocking cardiovascular effects induced by isoprenaline. H 56 28 I.C.I. 50172 have been shown possess intrinsic sympathomimetic activity; experiments increased rate decreased total peripheral resistance. did not alter systemic comparable response isoprenaline, while less potent. In contrast with earlier observations that β-receptor agents decrease coronary flow propranolol, 1999, practically no circulation All three resistance almost isoprenaline hemodynamics. a biphasic dose-dependent effect: smallest dose after largest one. This compound late diastolic potent than other antagonizing changes indicate hemodynamics, suggest it could be misleading extrapolate dogs man.