Evidence that an alpha 2A-adrenoceptor subtype mediates antinociception in mice.
In the hot-plate test in mice, the antinociceptive action of the alpha 2-adrenoceptor agonist, UK 14,304, was abolished by the alpha 2-adrenoceptor antagonist, idazoxan, the potent alpha 2A-adrenoceptor antagonist, RX 821002 and the preferential alpha 2A-adrenoceptor antagonist, BRL 44408. In contrast, the preferential alpha 2B- (and alpha 2C)-adrenoceptor ligands ('antagonists'), ARC-239, BRL 41992 and prazosin were inactive. The preferential alpha 2A-adrenoceptor partial agonist, guanfacine, partially inhibited UK 14,304-induced antinociception. Further, guanfacine BRL 44408 reversibly elicited submaximal antinociception. It is concluded that alpha 2A-adrenoceptors mediate antinociception in mice.
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CHEMICAL CHEMICAL GENE-N GENE-Y GENE-Y GENE-N GENE-Y GENE-Y GENE-N GENE-Y CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL
BRL 44408 UK 14,304 alpha 2-adrenoceptor alpha 2A-adrenoceptor alpha 2A-adrenoceptor alpha 2B- (and alpha 2C)-adrenoceptor alpha 2A-adrenoceptor alpha 2A-adrenoceptors alpha 2-adrenoceptor alpha 2A-adrenoceptor idazoxan RX 821002 BRL 44408 ARC-239 BRL 41992 prazosin guanfacine UK 14,304 guanfacine