Alpha 1-adrenoceptor antagonist decreases alpha 2-adrenoceptor antagonist-induced high voltage spindle suppression in adult and aged rats.
The present experiments were undertaken to study whether blockade of alpha 1-adrenoceptors would prevent the high-voltage spindle suppressing effect of atipamezole, an alpha 2-adrenoceptor antagonist. In adult rats, an alpha 1-adrenoceptor antagonist, prazosin, increased dose dependently the high voltage spindles in saline and atipamezole-pretreated rats. In addition, in aged rats prazosin blocked the high-voltage spindle suppressing action of atipamezole. Prazosin produced a smaller increase in high-voltage spindle values in aged than in adult rats. According to the present results, alpha 2-adrenoceptor antagonists may suppress high-voltage spindles indirectly by activating alpha 1-adrenoceptors in young and aged rats.
Riekkinen
P
P
University of Kuopio, Department of Neurology, Finland.
Sirviö
J
J
Toivanen
L
L
Riekkinen
M
M
Lammintausta
R
R
Riekkinen
P
P
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000375:Aging / Q000502:physiology*; D000818:Animals; D004569:Electroencephalography / Q000187:drug effects*; D007093:Imidazoles / Q000494:pharmacology; D008297:Male; D011224:Prazosin / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects* / Q000502:physiology*
D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D007093:Imidazoles; D011942:Receptors, Adrenergic, alpha; C050701:atipamezole; D011224:Prazosin