Detection of nonopioid β-endorphin receptor in the rat myocardium
Article first published online: 3 NOV 2011
Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
Journal of Peptide Science
Volume 18, Issue 2, pages 83–87, February 2012
How to Cite
Nekrasova, Y. N., Zolotarev, Y. A. and Navolotskaya, E. V. (2012), Detection of nonopioid β-endorphin receptor in the rat myocardium. J. Peptide Sci., 18: 83–87. doi: 10.1002/psc.1417
- Issue published online: 27 JAN 2012
- Article first published online: 3 NOV 2011
- Manuscript Accepted: 25 AUG 2011
- Manuscript Revised: 22 JUL 2011
- Manuscript Received: 9 JUN 2011
Two selective agonists of nonopioid β-endorphin receptor, synthetic peptides TPLVTLFK (octarphin) and SLTCLVKGFY (immunorphin), were labeled with tritium to specific activity of 29 and 25 Ci/mmol, respectively. Both labeled peptides were found to bind to high-affinity naloxone-insensitive binding sites on the membranes isolated from the rat myocardium (Kd = 2.0 ± 0.2 and 2.5 ± 0.3 nM, respectively). The [3H]octarphin specific binding to the myocardial membranes was inhibited by unlabeled β-endorphin (Ki = 1.9 ± 0.2 nM) and immunorphin (Ki = 2.2 ± 0.3 nM). The [3H]immunorphin specific binding with the membranes was inhibited by unlabeled β-endorphin (Ki = 2.3 ± 0.3 nM) and octarphin (Ki = 2.4 ± 0.3 nM). The binding specificity study revealed that these binding sites were insensitive not only to naloxone but also to α-endorphin, γ-endorphin, [Met5]enkephalin and [Leu5]enkephalin. Thus, β-endorphin, immunorphin and octarphin bind to the common high-affinity naloxone-insensitive receptor of the rat myocardial membranes. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.