α2-Adrenergic receptor binding in canine Purkinje fibers

Hon Chi Lee, Ricardo A. Samson, John J. Cai

Research output: Contribution to journalArticlepeer-review

5 Scopus citations

Abstract

Autoradiograms were developed from free running strands of Purkinje fibers and from left ventricular myocardium of dog hearts exposed to [7-methoxy-3H]prazosin or [O-methyl-3H]yohimbine in the presence or absence of excessive non-radioactive ligands. Both Purkinje fiber and ventricular myocardium showed high density, tissue-specific binding to [3H]prazosin. In contrast, high density, tissue-specific binding to [3H]yohimbine was present in Purkinje fibers but not in ventricular myocardium. Membrane fractions showed high affinity, saturable, and displaceable binding with [3H]yohimbine in preparations from canine cardiac Purkinje fibers hut not those from canine cardiac ventricular myocardium. Scatchard analysis of the canine Purkinje membrane α2-adrenergic receptor binding showed a B(max) of 54.9 fmol/mg protein with a K(d) of 6.25 nM. These results confirm the electrophysiological findings that post-junctional α2-adrenergic receptors are present in Purkinje fibers.

Original languageEnglish (US)
Pages (from-to)39-43
Number of pages5
JournalFEBS Letters
Volume380
Issue number1-2
DOIs
StatePublished - Feb 12 1996

Keywords

  • Autoradiography
  • Prazosin
  • Purkinje fibers
  • Receptor binding
  • Yohimbine
  • α-Adrenergic receptors
  • α-Adrenergic receptors

ASJC Scopus subject areas

  • Biophysics
  • Structural Biology
  • Biochemistry
  • Molecular Biology
  • Genetics
  • Cell Biology

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