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Agonist interactions with alpha-adrenergic receptors.

Publication ,  Journal Article
Hoffman, BB; Lefkowitz, RJ
Published in: J Cardiovasc Pharmacol
1982

alpha-Adrenergic receptors have been grouped into two major subtypes, termed alpha 1- and alpha 2-receptors. Radioligand binding techniques have been utilized to measure the number of alpha 1- and alpha 2-receptors in a variety of tissues. [3H]Dihydroergocryptine labels the entire alpha-receptor population; the alpha-receptor subtypes may be delineated by constricting competition curves with unlabeled selective antagonists and analyzing the data with computer modeling techniques. Alternatively, alpha 1- and alpha 2-receptors may be directly identified with selective radioligands such as [3H]prazosin and [3H]yohimbine, respectively. For example, rat liver membranes have been shown to contain alpha 1- (80%) and alpha 2- (20%) receptors; the alpha 1-receptors activate glycogen phosphorylase. Radioligands have also been used to probe the mechanism by which alpha 2-receptors may inhibit adenylate cyclase activity. Agonist competition curves with [3H]dihydroergocryptine at eht human platelet's alpha 2-receptor may be resolved into two affinity components, interconvertible by guanine nucleotides. These data suggest the agonist-promoted association of the alpha 2-receptor with an additional membrane component. More direct evidence in favor of this possibility was indicated by the increase in sedimentation velocity of solubilized agonist-labeled receptor on sucrose density gradients.

Duke Scholars

Published In

J Cardiovasc Pharmacol

DOI

ISSN

0160-2446

Publication Date

1982

Volume

4 Suppl 1

Start / End Page

S14 / S18

Location

United States

Related Subject Headings

  • Yohimbine
  • Receptors, Adrenergic, alpha
  • Receptors, Adrenergic
  • Rats
  • Prazosin
  • Liver
  • Ligands
  • Kinetics
  • Guanine Nucleotides
  • Cardiovascular System & Hematology
 

Citation

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Hoffman, B. B., & Lefkowitz, R. J. (1982). Agonist interactions with alpha-adrenergic receptors. J Cardiovasc Pharmacol, 4 Suppl 1, S14–S18. https://doi.org/10.1097/00005344-198200041-00004
Hoffman, B. B., and R. J. Lefkowitz. “Agonist interactions with alpha-adrenergic receptors.J Cardiovasc Pharmacol 4 Suppl 1 (1982): S14–18. https://doi.org/10.1097/00005344-198200041-00004.
Hoffman BB, Lefkowitz RJ. Agonist interactions with alpha-adrenergic receptors. J Cardiovasc Pharmacol. 1982;4 Suppl 1:S14–8.
Hoffman, B. B., and R. J. Lefkowitz. “Agonist interactions with alpha-adrenergic receptors.J Cardiovasc Pharmacol, vol. 4 Suppl 1, 1982, pp. S14–18. Pubmed, doi:10.1097/00005344-198200041-00004.
Hoffman BB, Lefkowitz RJ. Agonist interactions with alpha-adrenergic receptors. J Cardiovasc Pharmacol. 1982;4 Suppl 1:S14–S18.

Published In

J Cardiovasc Pharmacol

DOI

ISSN

0160-2446

Publication Date

1982

Volume

4 Suppl 1

Start / End Page

S14 / S18

Location

United States

Related Subject Headings

  • Yohimbine
  • Receptors, Adrenergic, alpha
  • Receptors, Adrenergic
  • Rats
  • Prazosin
  • Liver
  • Ligands
  • Kinetics
  • Guanine Nucleotides
  • Cardiovascular System & Hematology