Binding of 3H-β-endorphin in rat brain Article

Johnson, N, Houghten, R, Pasternak, GW. (1982). Binding of 3H-β-endorphin in rat brain . LIFE SCIENCES, 31(12-13), 1381-1384. 10.1016/0024-3205(82)90386-1

cited authors

  • Johnson, N; Houghten, R; Pasternak, GW

authors

abstract

  • The binding of 3H-β-endorphin to rat brain homogenates, reported by several other laboratories, has suggested unique selective β-endorphin binding sites. We now present additional evidence supporting the concept of distinct β-endorphin binding (epsilon) sites in rat brain. In competitive displacement studies, 3H-β-endorphin was inhibited far better by unlabeled β-endorphin than a variety of opiates and enkephalins. Conversely, β-endorphin inhibited the binding of a series of 3H-labeled ligands, including dihydromorphine, ethylketocyclazocine, SKF 10,047, naloxone and D-ala2-D-leu5-enkephalin, far less potently than their corresponding unlabeled drug. Other differences were also found. Compared to 3H-dihydromorphine and 3H-D-ala2-D-leu5-enkephalin in binding, 3H-β-endorphin binding was far less sensitive to the reagent N-ethylmaleimide and more sensitive to the proteolytic enzyme trypsin. The regional distribution for 3H-β-endorphin binding was also distinct from other 3H-ligands tested. This evidence supports the concept of a distinct binding site for β-endorphin which does not correspond to the previously defined opioid binding sites. © 1982.

publication date

  • January 1, 1982

published in

Digital Object Identifier (DOI)

start page

  • 1381

end page

  • 1384

volume

  • 31

issue

  • 12-13