• Corpus ID: 28050975

Effects of beta adrenoceptor down-regulation on the cardiovascular responses to the stereoisomers of dobutamine.

  title={Effects of beta adrenoceptor down-regulation on the cardiovascular responses to the stereoisomers of dobutamine.},
  author={James Scott Hayes and Nancy Bowling and G. Donald Pollock},
  journal={The Journal of pharmacology and experimental therapeutics},
  volume={235 1},
Effects of prolonged in vivo infusion of either saline (control) or isoproterenol (beta adrenoceptor desensitization) on acute cardiovascular responses to (+) (beta agonist)-, (-) (alpha agonist)- and (+/-)-dobutamine were studied in pithed rats. Each form of dobutamine resulted in comparable dose-dependent increases in maximum left ventricular dP/dt (LVdP/dtmax) in control animals. Effects of (+)-dobutamine were blocked by propranolol whereas those of l-dobutamine were sensitive to prazosin… 

Chronotropic and inotropic responses to adrenoceptor agonists in vitro after chronic dobutamine treatment in the rabbit.

  • M. Brown
  • Biology, Medicine
    Journal of autonomic pharmacology
  • 1992
These changes are consistent with functional desensitization of the myocardium by the prolonged beta- but not alpha 1-agonist activity of dobutamine, and there was an enhanced effectiveness of beta-adrenoceptor activation.

Myocardial chronotropic and inotropic responsiveness in vitro after chronic α‐adrenoreceptor blockade in the rat

The results show selectivity of action of chronic prazosin treatment on alpha 1-receptors in the rat heart, but both beta-mediated inotropic and chronotropic responses were unaffected.

Intracoronary infusion of dobutamine to patients with and without severe congestive heart failure. Dose-response relationships, correlation with circulating catecholamines, and effect of phosphodiesterase inhibition.

The maximal inotropic response to dobutamine is markedly depressed in patients with severe CHF, and is significantly greater after pretreatment with the phosphodiesterase inhibitor milrinone; the impairment in inotropic responded is inversely related to circulating norepinephrine levels; and myocardial stimulation by dobutamines results in withdrawal of sympathetic tone.

Effects of Myocardial α1‐Adrenergic Receptor Stimulation and Blockade on Contractility in Humans

The α-adrenergic receptor-selective antagonist phentolamine and agonist phenylephrine were infused directly into the left main coronary artery and the change in contractile state was assessed by measuring left ventricular peak (+)dP/dt, and stimulation of myocardial α- adrenergic receptors exerts a positive inotropic effect, which may be attenuated in patients with heart failure.

Myocardial effects of adrenaline, isoprenaline and dobutamine at hypothermic conditions.

The pharmacodynamic myocardial effects of adrenaline, isoprenaline and dobutamine were studied in isolated, perfused and spontaneously beating rabbit hearts at hypothermic conditions and a marked left-shift of the log-concentration response curves was observed as an expression of increased myocardials sensitivity to the drugs.

Cardiovascular actions of OPC-18790: A novel positive inotropic agent with little chronotropic action

The cardiovascular effects revealed by this study suggest that OPC-18790 may exert a beneficial effect in the treatment of congestive heart failure.

IV. Neurohumoral Mechanisms in Heart Failure /3-Adrenergic Inotropic Responsiveness of Patients With Heart Failure: Studies With Intracoronary Dobutamine Infusion

Support is provided for the view that patients with severe congestive heart failure and a markedly elevated resting plasma norepinephrine concentration have a reduced myocardial inotropic response to /3-adrenergic receptor stimulation and suggest that the degree of sympathetic nervous system activation may be one factor involved in determining the level of myocardials inotropic receptor sensitivity.

The hemodynamic effects of dobutamine infusion in the chronically instrumented newborn piglet.

Prolonged infusion of dobutamine at 10 microg/kg x min progressively increases cardiac output and stroke volume with transient tachycardia, and increases mesenteric and renal blood flows, which could also reduce systemic to pulmonary arterial pressure ratio.

Myocardial beta-adrenoceptor function and regulation in heart failure: implications for therapy.

  • D. Barnett
  • Medicine, Biology
    British journal of clinical pharmacology
  • 1989
There has, however, been a recent resurgence of interest in alternative approaches to direct inotropism and related to this the possible deleterious effect of chronic myocardial Iadrenoceptor over stimulation during the development of heart failure.