Evidence for a non-opioid sigma binding site in the guinea-pig myenteric plexus

Life Sci. 1988;42(22):2217-22. doi: 10.1016/0024-3205(88)90373-6.

Abstract

The presence of a binding site to (+)-(3H)SKF 10,047 was demonstrated in a guinea-pig myenteric plexus (MYP) membrane preparation. Specific binding to this receptor was saturable, reversible, linear with protein concentration and consisted of two components, a high affinity site (KD = 46 +/- 5 nM; Bmax = 3.4 +/- 0.5 pmole/g wet weight) and a low affinity site (KD= = 342 +/- 72 nM; Bmax = 22 +/- 3 pmole/g wet weight). Morphine and naloxone 10(-4) M were unable to displace (+)-(3H)SKF 10,047 binding. Haloperidol, imipramine, ethylketocyclazocine and propranolol were among the most potent compounds to inhibit this specific binding. These results suggest the presence of a non-opioid haloperidol sensitive sigma receptor in the MYP of the guinea-pig.

MeSH terms

  • Animals
  • Binding, Competitive
  • Cell Membrane / metabolism
  • Chlorpromazine / metabolism
  • Cyclazocine / analogs & derivatives
  • Cyclazocine / metabolism
  • Ethylketocyclazocine
  • Guinea Pigs
  • Haloperidol / metabolism
  • Imipramine / metabolism
  • Male
  • Myenteric Plexus / metabolism*
  • Phenazocine / analogs & derivatives
  • Phenazocine / metabolism
  • Propranolol / metabolism
  • Receptors, Opioid / metabolism*
  • Receptors, sigma

Substances

  • Receptors, Opioid
  • Receptors, sigma
  • Ethylketocyclazocine
  • SK&F 10047
  • Propranolol
  • Phenazocine
  • Cyclazocine
  • Haloperidol
  • Imipramine
  • Chlorpromazine