Erysodine, a competitive antagonist at neuronal nicotinic acetylcholine receptors

Eur J Pharmacol. 1995 Jun 23;280(1):79-89. doi: 10.1016/0014-2999(95)00191-m.


Erysodine, an erythrina alkaloid related to dihydro-beta-erythroidine, was found to be a more potent inhibitor of [3H]cytisine binding at neuronal nicotinic acetylcholine receptors but a less potent inhibitor of [125I]alpha-bungarotoxin binding at muscle-type nicotinic acetylcholine receptors than dihydro-beta-erythroidine. Erysodine was a competitive, reversible antagonist of (-)-nicotine-induced dopamine release from striatal slices and inhibited (-)-nicotine-induced 86Rb+ efflux from IMR-32 cells. Erysodine was equipotent with dihydro-beta-erythroidine in the dopamine release assay but 10-fold more potent in the 86Rb+ efflux assay, suggesting differential subtype selectivity for these two antagonists. Erysodine, systemically administered to mice, entered the brain and significantly attentuated nicotine's hypothermic effects and its anxiolytic-like effects in the elevated plus-maze test. There was greater separation between antagonist and toxic doses for erysodine than for dihydro-beta-erythroidine, perhaps because of erysodine's greater selectivity for neuronal receptors. In rats, erysodine prevented both the early developing decrease and the late-developing increase in locomotor activity produced by (-)-nicotine. The potent and competitive nature of erysodine's antagonism together with its ability to enter the brain after systemic administration suggest that erysodine may be a useful tool in characterizing neuronal nicotinic acetylcholine receptors.

MeSH terms

  • Alkaloids / metabolism
  • Animals
  • Azocines
  • Behavior, Animal / drug effects
  • Binding, Competitive
  • Corpus Striatum / drug effects
  • Corpus Striatum / metabolism
  • Dihydro-beta-Erythroidine / analogs & derivatives*
  • Dihydro-beta-Erythroidine / pharmacology
  • Dopamine / metabolism
  • Locomotion / drug effects
  • Male
  • Mice
  • Mice, Inbred Strains
  • Muscles / metabolism
  • Muscles / ultrastructure
  • Neuroblastoma / metabolism
  • Neurons / metabolism
  • Neurons / ultrastructure*
  • Nicotinic Antagonists / pharmacology*
  • Quinolizines
  • Rats
  • Rats, Sprague-Dawley
  • Rats, Wistar
  • Rubidium / pharmacokinetics
  • Rubidium Radioisotopes
  • Temperature
  • Tritium
  • Tumor Cells, Cultured


  • Alkaloids
  • Azocines
  • Nicotinic Antagonists
  • Quinolizines
  • Rubidium Radioisotopes
  • Tritium
  • Dihydro-beta-Erythroidine
  • cytisine
  • erysodine
  • Rubidium
  • Dopamine