title: Blockade of MK-801 induced ipsiversive turning in 6-OHDA lesioned rats by alpha 1-adrenoceptor antagonists.
abstract: Previously the ipsiversive turning response elicited by MK-801 in rats with unilateral 6-hydroxydopamine lesions of the substantia nigra has been shown to be reduced by the alpha 1-receptor antagonist, prazosin. In these experiments the effects of additional alpha 1-adrenoceptor antagonists were examined to verify the involvement of alpha 1-adrenoceptors in the elucidation of the ipsiversive turning response elicited by MK-801. Both aceperone and azapetine did significantly reduce the ipsiversive turning evoked by MK-801. In contrast, neither agent produced a statistically significant reduction in the contraversive turning evoked by the direct acting dopamine agonist, apomorphine. In addition, aceperone also produced a weak but dose-related inhibition of amphetamine-induced ipsiversive rotation, whereas azapetine partially reduced amphetamine-induced turning a non-dose related manner. These data suggest alpha 1-adrenoceptors may be partially involved in the ipsiversive turning response caused by MK-801 and to a lesser extent by amphetamine. This theory was further supported by the finding that reduction of endogenous norepinephrine levels, via administration of the dopamine-beta-hydroxylase inhibitor FLA-63, markedly reduced the turning evoked by MK-801 and to a lesser degree that produced by amphetamine.
mesh_terms: D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000661:Amphetamine / Q000494:pharmacology; D000818:Animals; D000927:Anticonvulsants / Q000037:antagonists & inhibitors / Q000494:pharmacology; D005406:Bis(4-Methyl-1-Homopiperazinylthiocarbonyl)disulfide / Q000494:pharmacology; D002090:Butyrophenones / Q000494:pharmacology; D003984:Dibenzazepines / Q000494:pharmacology; D003986:Dibenzocycloheptenes / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D016291:Dizocilpine Maleate; D005260:Female; D006801:Humans; D006892:Hydroxydopamines / Q000494:pharmacology*; D016627:Oxidopamine; D004856:Postural Balance / Q000187:drug effects; D011224:Prazosin / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013239:Stereotyped Behavior / Q000187:drug effects*; D013378:Substantia Nigra / Q000502:physiology
chemical_list: D000317:Adrenergic alpha-Antagonists; D000927:Anticonvulsants; D002090:Butyrophenones; D003984:Dibenzazepines; D003986:Dibenzocycloheptenes; D006892:Hydroxydopamines; D005406:Bis(4-Methyl-1-Homopiperazinylthiocarbonyl)disulfide; D016291:Dizocilpine Maleate; D016627:Oxidopamine; C004448:azapetine; D000661:Amphetamine; D011224:Prazosin