Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
POTENTIATION OF BARBITURATE-INDUCED ALTERATIONS IN PRESYNAPTIC NORADRENERGIC FUNCTION IN RAT FRONTAL-CORTEX BY IMIDAZOL(IN)E ALPHA(2)-ADRENOCEPTOR AGONISTS
Autore:
DALLEY JW; PARKER CA; WULFERT E; HUDSON AL; NUTT DJ;
Indirizzi:
UNIV CAMBRIDGE,DEPT EXPT PSYCHOL,DOWNING ST CAMBRIDGE CB2 3EB ENGLAND UNIV BRISTOL,PSYCHOPHARMACOL UNIT BRISTOL BS8 1TD AVON ENGLAND UCB PHARMA SA B-1420 BRUSSELS BELGIUM
Titolo Testata:
British Journal of Pharmacology
fascicolo: 3, volume: 125, anno: 1998,
pagine: 441 - 446
SICI:
0007-1188(1998)125:3<441:POBAIP>2.0.ZU;2-A
Fonte:
ISI
Lingua:
ENG
Soggetto:
DEPENDENT PROTEIN-KINASE; GAMMA-AMINOBUTYRIC ACID; ANESTHETIC REQUIREMENTS; A RECEPTOR; DEXMEDETOMIDINE; RELEASE; BRAIN; CLONIDINE; GABA; NORADRENALINE;
Keywords:
MIVAZEROL; CLONIDINE; PENTOBARBITAL; NORADRENALINE; GABA; ANESTHESIA;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
32
Recensione:
Indirizzi per estratti:
Citazione:
J.W. Dalley et al., "POTENTIATION OF BARBITURATE-INDUCED ALTERATIONS IN PRESYNAPTIC NORADRENERGIC FUNCTION IN RAT FRONTAL-CORTEX BY IMIDAZOL(IN)E ALPHA(2)-ADRENOCEPTOR AGONISTS", British Journal of Pharmacology, 125(3), 1998, pp. 441-446

Abstract

1 In order to resolve the extent to which presynaptic noradrenergic mechanisms contribute to the anaesthetic-sparing effects of alpha(2)-adrenoceptor agonists in vivo microdialysis was used to investigate the combined effects of sodium pentobarbitone and imidazol(in)e alpha(2)-adrenoceptor agonists on extracellular levels of noradrenaline (NA) in the rat frontal cortex. 2 Dialysate levels of NA were markedly reducedby the addition of TTX (2 mu M) or by the removal of calcium in the perfusate. These data imply that dialysate NA. levels are ultimately dependent on exocytotic release mechanisms from afferent coeruleo-cortical neurones. 3 Systemic administration of sodium pentobarbitone (85 mgkg(-1), i.p.) induced general anaesthesia and reduced NA levels by 92% after 30 min. The restoration of basal levels 90 min later was closely associated with a return of the corneal blink reflex. 4 Basal NA levels in conscious animals were not affected by an intravenous infusionof equally radioactive solutions of either imidazoline (clonidine) orimidazole (miverazol) alpha(2)-adrenoceptor agonists. The dose rate employed for each compound was 2 mu g kg(-1) h(-1) over 2 h. 5 The co-administration of intravenous clonidine or mivazerol: each at 2 mu g kg(-1) h(-1) for 2 h, with sodium pentobarbitone (85 mg kg(-1), i.p.), produced a marked and prolonged reduction in NA efflux. After 2 h, NA levels remained suppressed by 95% (clonidine:) and 80% (mivazerol) and animals remained deeply anaesthetized. 6 The accumulation of tritium in brain tissue was 42-73% lower across all brain regions examined after [H-3]-mivazerol administration than after [H-3]-clonidine administration. Sodium pentobarbitone did not alter the accumulation of tritium in brain tissue after the administration of either alpha(2)-adrenoceptor agonist. 7 These data demonstrate that alpha(2)-adrenoceptor agonists potentiate the inhibitory effects of sodium pentobarbitone on extracellular levels of NA in the frontal cortex. Further studies will be necessary to establish a causal role of noradrenergic mechanisms in thepotentiation of anaesthesia by selective alpha(2)-adrenoceptor agonists.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 29/03/20 alle ore 11:44:05