These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Synthesis and characterization of arylamine derivatives of rauwolscine as molecular probes for alpha 2-adrenergic receptors.
    Author: Lanier SM, Graham RM, Hess HJ, Grodski A, Repaske MG, Nunnari JM, Limbird LE, Homcy CJ.
    Journal: Hypertension; 1987 Jun; 9(6 Pt 2):III120-4. PubMed ID: 2885270.
    Abstract:
    The selective alpha 2-adrenergic receptor antagonist rauwolscine was structurally modified to yield a series of arylamine carboxamide derivatives, which were investigated as potential molecular probes for the localization and structural characterization of alpha 2-adrenergic receptors. The arylamine carboxamides differ in the number of carbon atoms separating the reactive phenyl moiety from the fused ring structure of the parent compound, rauwolscine carboxylate. Competitive inhibition studies with [3H]rauwolscine in rat kidney membranes indicate that the affinity for the carboxamide derivatives is inversely related to the length of the carbon spacer arm with rauwolscine 4-aminophenyl carboxamide (zero carbon spacer arm; rau-AMPC) exhibiting the highest affinity (Kd = 2.3 +/- 0.2 nM). Radioiodination of rau-AMPC yields a ligand, 125I-rau-AMPC, which binds to rat kidney alpha 2-adrenergic receptors with high affinity, as determined by both kinetic analysis (Kd = k2/k1 = 0.016 min-1/2.1 X 10(7) M-1 min-1 = 0.76 nM) and equilibrium binding studies (Kd = 0.78 +/- 0.16 nM). 125I-rau-AMPC was quantitatively converted to the photolabile arylazide derivative 17 alpha-hydroxy-20 alpha-yohimban-16 beta-(N-4-azido-3-[125I]iodophenyl) carboxamide (125I-rau-AZPC). In a partially purified receptor preparation from porcine brain, this compound photolabels a major (Mr = 62,000) peptide. The labeling of this peptide is inhibited by adrenergic agonists and antagonists with a rank order of potency consistent with an alpha 2-adrenergic receptor binding site. Both 125I-rau-AMPC and the photolabile arylazide derivative, 125I-rau-AZPC, should prove useful as molecular probes for the structural and biochemical characterization of alpha 2-adrenergic receptors.
    [Abstract] [Full Text] [Related] [New Search]