Behavioral effects of GABA(A) receptor stimulation and GABA-transporter inhibition

Pharmacol Biochem Behav. 2000 Feb;65(2):351-6. doi: 10.1016/s0091-3057(99)00208-7.

Abstract

The present analysis addressed behavioral changes after treatment with 4.5 mg/kg or 18.5 mg/kg of the GABA-uptake inhibitor tiagabine combined with either the benzodiazepine diazepam (1.5 mg/kg) or the imidazopyridine zolpidem (0.05 mg/kg), the latter two acting differentially on GABA(A) receptor subtypes. The study included 97 male PVG/OIaHsd rats. A standard open field, an enriched open field, and an elevated plus-maze was used to study rat behavior. Treatment with the low dose of tiagabine alone induced no specific behavioral effects, whereas the high dose had an anxiolytic-like potential. Furthermore, diazepam but not zolpidem displayed anxiolytic-like effects. Combination of each benzodiazepine receptor agonist with tiagabine at the low dose decreased explorative activity. Diazepam plus the high dose of tiagabine increased the activity in the open-field test. Zolpidem together with 18.5 mg/kg tiagabine had an angiogenic-like effect compared to pure tiagabine treatment. These results provide evidence for a pharmacodynamic interaction between the GABA-uptake inhibitor tiagabine and diazepam or zolpidem. The interaction might be relevant in the clinic when combining the anticonvulsant tiagabine and a benzodiazepine receptor agonist.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Behavior, Animal / drug effects*
  • Carrier Proteins / antagonists & inhibitors*
  • Drug Interactions
  • Drug Therapy, Combination
  • GABA Plasma Membrane Transport Proteins
  • Hypnotics and Sedatives / pharmacology*
  • Male
  • Membrane Proteins / antagonists & inhibitors*
  • Membrane Transport Proteins*
  • Motor Activity / drug effects*
  • Neurotransmitter Uptake Inhibitors / pharmacology*
  • Nipecotic Acids / pharmacology*
  • Organic Anion Transporters*
  • Pyridines / pharmacology*
  • Rats
  • Receptors, GABA-A / drug effects*
  • Tiagabine
  • Zolpidem

Substances

  • Carrier Proteins
  • GABA Plasma Membrane Transport Proteins
  • Hypnotics and Sedatives
  • Membrane Proteins
  • Membrane Transport Proteins
  • Neurotransmitter Uptake Inhibitors
  • Nipecotic Acids
  • Organic Anion Transporters
  • Pyridines
  • Receptors, GABA-A
  • Zolpidem
  • Tiagabine