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 language | English (US) |
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Pages (from-to) | 39-43 |
Number of pages | 5 |
Journal | FEBS Letters |
Volume | 380 |
Issue number | 1-2 |
DOIs | |
State | Published - Feb 12 1996 |
Externally published | Yes |
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