2Institute of Molecular Genetics, Russian Academy of Sciences, pl. Kurchatova 2, 123182 Moscow, Russia; fax: (495) 196-0221; E-mail: firstname.lastname@example.org
* To whom correspondence should be addressed.
Received April 19, 2011; Revision received May 21, 2011
A selective agonist of non-opioid β-endorphin receptor synthetic peptide octarphin (TPLVTLFK, specific activity 28 Ci/mmol) was prepared. The [3H]octarphin binding to rat myocardium membranes before and after experimental myocardial infarction (EMI) was studied. It was found that [3H]octarphin with high affinity and specificity binds to non-opioid β-endorphin receptor of rat myocardium membranes before EMI: Kd1 value of the [3H]octarphin specific binding to membranes was 1.8 ± 0.2 nM. In 3 h after EMI a sharp lowering in affinity of the binding is observed (Kd2 = 13.3 ± 0.4 nM), and in 48 h its almost complete restoration (Kd4 = 2.2 ± 0.3 nM). The results indicate participation of non-opioid β-endorphin receptor in the regulation of myocardial activity.
KEY WORDS: β-endorphin, naloxone, peptide, receptor, myocardium