Regulation of Myocardial and Vascular a‐Adrenergic Receptor Affinity: Effects of Guanine Nucleotides, Cations, Estrogen, and Catecholamine Depletion

@article{Colucci1984RegulationOM,
  title={Regulation of Myocardial and Vascular a‐Adrenergic Receptor Affinity: Effects of Guanine Nucleotides, Cations, Estrogen, and Catecholamine Depletion},
  author={Wilson S. Colucci and Michael A. Jr Gimbrone and R. Wayne Alexander and Gwendolyn M. Wise},
  journal={Circulation Research},
  year={1984},
  volume={55},
  pages={78–88}
}
The threshold sensitivity of cardiovascular tissues to α-adrenergic stimulation is determined largely by the affinity of a-adrenergic receptors for agonists. To determine whether changes in a-adrenergic receptor affinity could contribute to the regulation of cardiac and vascular responsiveness, we used the a-adrenergic-selective radioligands, [3H]prazosin, [3H]-WB-4101, and [3H]rauwalscine, to study and contrast the determinants of a-adrenergic receptor affinity in myocardium and vascular… 
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Citation Type

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TLDR
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  • Biology
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  • 1989
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TLDR
In rabbit papillary muscle, the time course of increase in contractile force induced by a-adrenoceptors coincided with the prolongation of the action potential duration with a similar time course, which is in strong contrast to previous findings in rat that the contractile response was dissociated from the electrophysiological response to e- adrenoceptor stimulation.
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TLDR
The results indicate the presence of a PT-insensitive G protein in the neonatal and adult rat heart and the acquisition of aPT-sensitive G protein linked to the negative chronotropic response during development.
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TLDR
In rabbit papillary muscle, the time course of increase in contractile force induced by a-adrenoceptors coincided with the prolongation of the action potential duration with a similar time course, which is in strong contrast to previous findings in rat that the contractile response was dissociated from the electrophysiological response to e- adrenoceptor stimulation.
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References

SHOWING 1-10 OF 53 REFERENCES
Regulation of the Postsynaptic α‐Adrenergic Receptor in Rat Mesenteric Artery: Effects of Chemical Sympathectomy and Epinephrine Treatment 1981
Vascular smooth muscle sensitivity to catecholamine-induced contraction is increased after catecholamine depletion by chemical sympathectomy and decreased after exogenous catecholα-mine…
Guanine nucleotides and alpha 1 adrenergic receptors in the heart.
Characterization of Postsynaptic Alpha‐Adrenergic Receptors by [8H]‐Dihydroergocryptine Binding in Muscular Arteries from the Rat Mesentery
TLDR
The extension of radiollgand binding techniques to highly innervated muscular arteries of the type contributing to rascular resistance will allow the study of the role of the vascular a-adrenergic receptor in various physiologic states and models of hypertension.
Characterization of alpha-1 adrenergic receptors in the heart using [3H]WB4101: effect of 6-hydroxydopamine treatment.
TLDR
6-hydroxydopamine treatment caused a significant increase in the density of alpha-1 adrenoceptors in ventricles and intraventricular septae, compatible with a postsynaptic localization of the [3H]WB4101 binding site.
Characterization of alpha-adrenergic receptor subtypes in the rat renal cortex. Differential regulation of alpha 1- and alpha 2-adrenergic receptors by guanyl nucleotides and Na.
TLDR
The findings with renal cortical membranes indicate that regulation of agonist binding at alpha-adrenergic receptor subtypes by guanyl nucleotides and Na+ is not limited to alpha 2- adrenergic receptors, as previously reported with other tissues.
Increased Vascular Catecholamine Sensitivity and α‐Adrenergic Receptor Affinity in Female and Estrogen‐Treated Male Rats
TLDR
It is demonstrated that estrogens increase the affinity of α-adrenergic receptors in blood vessels, and evidence that the estrogen-induced increase in vascular sensitivity to catecholamine-induced contraction is mediated, at least in part, by these affinity changes is provided.
Angiotensin II receptors in bovine adrenal cortex. Modification of angiotensin II binding by guanyl nucleotides.
TLDR
It is proposed that the actions of the guanyl nucleotides are based on a conformational change at the receptor level that leads to a lower steady state binding of the hormone to its receptor and a rapid release of bound tracer angiotensin II.
Sodium, Divalent Cations, and Guanine Nucleotides Regulate the Affinity of the Rat Mesenteric Artery Angiotensin II Receptor
TLDR
It is concluded that cations and guanine nucleotides interact in one or more receptor-associated membrane sites, probably including the guanINE nucleotide regulatory protein, to modulate the affinity of the vascular receptor for angiotensin II.
Characterization of the rabbit ventricular myocardial receptor for angiotensin II. Evidence for two sites of different affinities and specificities.
TLDR
The physiological implications of the presence in ventricular myocardium of two distinct angiotensin II receptors and in particular the implications of a receptor-associated guanine nucleotide regulatory protein which does not couple to adenylate cyclase require further investigation.
Potentiation by hydrocortisone of responses to catecholamines in vascular smooth muscle.
  • J. Besse, A. Bass
  • Biology, Medicine
    The Journal of pharmacology and experimental therapeutics
  • 1966
TLDR
It is suggested that HC increases the affinity of the catecholamine or possibly its p-hydroxy analog for the adrenergic receptor by modifying the interaction of the p -hydroxyl group in the molecule with the receptor.
...
1
2
3
4
5
...