Methyllycaconitine and (+)-anatoxin-a differentiate between nicotinic receptors in vertebrate and invertebrate nervous systems

FEBS Lett. 1988 Jan 4;226(2):357-63. doi: 10.1016/0014-5793(88)81454-6.

Abstract

Specific high-affinity binding sites for 125I-alpha-bungarotoxin and (-)-[3H]nicotine have been measured in rat brain and locust (Schistocerca gregaria) ganglia. The binding sites for 125I-alpha-bungarotoxin had similar Kd values of 1.5 x 10(-9) and 0.8 x 10(-9) M for rat and locust preparations, respectively; the corresponding values for the (-)-[3H]nicotine-binding site were 9.3 x 10(-9) and 1.7 x 10(-7) M. Methyllycaconitine (MLA) potently inhibited 125I-alpha-bungarotoxin binding in both rat and locust. MLA was a less effective inhibitor of (-)-[3H]nicotine binding whereas (+)-anatoxin-a was a very potent inhibitor at this site in the rat but not in the locust. These data suggest that (+)-anatoxin-a is a useful probe for the high-affinity nicotine-binding receptor in vertebrate brain, whereas MLA is a preferential probe for the subclass of receptor that binds alpha-bungarotoxin.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aconitine / analogs & derivatives*
  • Aconitine / pharmacology
  • Aconitum / analogs & derivatives*
  • Animals
  • Bacterial Toxins*
  • Binding, Competitive
  • Brain / metabolism*
  • Bungarotoxins / metabolism
  • Cyanobacteria Toxins
  • Ganglia / metabolism
  • Grasshoppers / metabolism*
  • Kinetics
  • Marine Toxins / pharmacology*
  • Microcystins
  • Nicotine / metabolism
  • Rats
  • Receptors, Nicotinic / drug effects
  • Receptors, Nicotinic / metabolism*
  • Species Specificity
  • Tropanes

Substances

  • Bacterial Toxins
  • Bungarotoxins
  • Cyanobacteria Toxins
  • Marine Toxins
  • Microcystins
  • Receptors, Nicotinic
  • Tropanes
  • methyllycaconitine
  • Nicotine
  • anatoxin a
  • Aconitine