Blocking actions of BIDN, a bicyclic dinitrile convulsant compound, on wild-type and dieldrin-resistant GABA receptor homo-oligomers of Drosophila melanogaster expressed in Xenopus oocytes

Brain Res. 1995 Sep 25;693(1-2):257-60. doi: 10.1016/0006-8993(95)00605-p.

Abstract

The receptor antagonist actions are described for a novel bicyclic dinitrile compound (BIDN, 3,3-bis-(trifluoromethyl)-bicyclo [2.2.1] heptane-2,2-dicarbonitrile) on a Drosophila melanogaster homo-oligomeric GABA receptor expressed in Xenopus oocytes. BIDN blocked the wild-type form of the receptor in a neither purely competitive, nor purely non-competitive manner, being dependent on the GABA concentration yet insurmountable, and block was independent of the membrane potential. BIDN was found to be less effective against a mutant (A(302) --> S) form of the receptor resistant to dieldrin and picrotoxinin. This cross resistance of dieldrin-resistant receptors to BIDN is of interest in the light of recent findings that BIDN binding to insect membranes is displaced competitively by dieldrin, but not by picrotoxinin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bridged Bicyclo Compounds / pharmacology*
  • Chloride Channels / antagonists & inhibitors
  • Convulsants / pharmacology*
  • Dieldrin / pharmacology
  • Drosophila melanogaster / chemistry*
  • Electrophysiology
  • GABA Antagonists / pharmacology*
  • Gene Expression / physiology
  • Microinjections
  • Nitriles / pharmacology*
  • Oligopeptides
  • Oocytes / physiology
  • Receptors, GABA / genetics
  • Receptors, GABA / ultrastructure
  • Xenopus

Substances

  • Bridged Bicyclo Compounds
  • Chloride Channels
  • Convulsants
  • GABA Antagonists
  • Nitriles
  • Oligopeptides
  • Receptors, GABA
  • 3,3-bis(trifluoromethyl)bicyclo(2.2.1)heptane-2,2-dicarbonitrile
  • Dieldrin