Some unusual effects of alpha 2-adrenergic drugs on cortical high voltage spindles in rats.
The dose-response curves for a number of alpha-adrenergic drugs were investigated to estimate a possible role of the alpha 2/alpha 1 selectivity of these drugs on the incidence of cortical high voltage spindles (HVS), reflecting level of vigilance. The alpha 2 antagonists yohimbine (0.25-4 mg/kg) and idazoxan (0.5-4 mg/kg), but not atipamezole induced a biphasic effect on the incidence of HVS in rats. This effect of relatively small doses of yohimbine and idazoxan should be taken into consideration when using these drugs as alpha 2 antagonists in behavioral and neurophysiological tests. On the other hand the linearity of the dose-response curve for atipamezole (0.01-4 mg/kg) indicates that this drug is a good candidate for use in such tests.
Yavich
L
L
Department of Neurology, University of Kuopio, Finland.
Sirviö
J
J
Haapalinna
A
A
Riekkinen
P
P
D058646:Adrenergic alpha-1 Receptor Agonists; D058668:Adrenergic alpha-1 Receptor Antagonists; D058647:Adrenergic alpha-2 Receptor Agonists; D058669:Adrenergic alpha-2 Receptor Antagonists; D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects*; D004146:Dioxanes / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004594:Electrophysiology; D019329:Idazoxan; D007093:Imidazoles / Q000494:pharmacology; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D015016:Yohimbine / Q000494:pharmacology
D058646:Adrenergic alpha-1 Receptor Agonists; D058668:Adrenergic alpha-1 Receptor Antagonists; D058647:Adrenergic alpha-2 Receptor Agonists; D058669:Adrenergic alpha-2 Receptor Antagonists; D004146:Dioxanes; D007093:Imidazoles; C050701:atipamezole; D015016:Yohimbine; D019329:Idazoxan