text: 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.