Analgesic action of alpha-adrenolytics in albino mice

The effect of alpha-adrenolytics: phenoxybenzamine, phentolamine, aceperone, dihydroegotamine, and yohimbine, was tested on reactivity to pain, and on the analgesic action of morphine and pethidine in albino mice. The compounds exert an analgesic effect by themselves, and potentiate the analgesic action of threshold doses of morphine and pethidine. The results seem to provide another proof that the cerbral noradrenaline neurons participate in central mechanisms of pain perception.