title: Effect of cocaine on responsiveness of alpha(1)-adrenergic receptors in rat cerebral cortex: modulation by GABA-mimetic drugs.
abstract: We investigated the effects of single doses of cocaine (10 mg/kg, ip) and the gamma-aminobutyric acid (GABA)-mimetics tiagabine (10 mg/kg, ip) and vigabatrin (150 mg/kg, ip) injected separately or concomitantly with cocaine, on the responsiveness of cerebral cortical alpha(1)-adrenergic receptors. The accumulation of noradrenaline-stimulated inositol phosphates was estimated in vitro at 2 and 24 h after the drug injection. Cocaine significantly enhanced alpha(1)-adrenergic receptor responsiveness to noradrenaline. Neither tiagabine nor vigabatrin influenced the accumulation of inositol phosphates. Finally, the cocaine-evoked augmentation of alpha(1)-adrenoceptor responsiveness was counteracted by tiagabine but not by vigabatrin. This effect may represent a characteristic feature of tiagabine, not necessarily shared by other GABA-mimetic drugs.
authors.affiliation: Department of Brain Biochemistry, Institute of Pharmacology, Polish Academy of Science, Smetna 12, PL 31-343 Kraków, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Wieczerzak
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Witarski
authors.forename: Marta
authors.initials: M
authors.lastname: Kowalska
authors.forename: Dominika
authors.initials: D
authors.lastname: Nawrat
authors.forename: Adam
authors.initials: A
authors.lastname: Roman
authors.forename: Adam
authors.initials: A
authors.lastname: Bielawski
authors.forename: Irena
authors.initials: I
authors.lastname: Nalepa
mesh_terms: D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects* / Q000502:physiology; D003042:Cocaine / Q000494:pharmacology*; D007295:Inositol Phosphates / Q000378:metabolism; D008297:Male; D009557:Nipecotic Acids / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D018340:Receptors, Adrenergic, alpha-1 / Q000502:physiology*; D000078308:Tiagabine; D020888:Vigabatrin / Q000494:pharmacology*
chemical_list: D007295:Inositol Phosphates; D009557:Nipecotic Acids; D018340:Receptors, Adrenergic, alpha-1; D020888:Vigabatrin; D003042:Cocaine; D000078308:Tiagabine