• 1 January 1982
    • journal article
    • research article
    • Vol. 257  (2) , 200-212
Abstract
Effects of emorfazone [an analgesic] on the nociceptive responses induced by the liminal dose of bradykinin (BK alone-induced response), the combined use of the subliminal dose of BK and prostaglandin E (PGE-potentiated response) and the electrical stimulation of the sensory nerve were investigated. BK and PGE were injected into the femoral artery of dogs and the right common carotid artery of rats. In lightly anesthetized dogs, emorfazone (5-20 mg/kg, i.v.), aminopyrine (30 mg/kg, i.v.) and aspirin (50 mg/kg, i.v.) inhibited the vocalization response induced by BK alone, but not by the electrical stimulation of the saphenous nerve. Unlike morphine hydrochloride, these drugs showed a blocking action on the saphenous nerve activity evoked by BK. These 3 drugs differed from one another with respect to the action on the PGE-potentiated response; emorfazone inhibited the PGE-potentiated response to the same extent as in the case of the BK alone-induced response, while aminopyrine was less active in inhibiting the PGE-potentiated response than BK alone-induced response and aspirin showed no action on the PGE-potentiated response. Such mode of action of emorfazone on BK-induced nociception was confirmed with a similar experiment using conscious rats. The main site of antinociceptive action of emorfazone may be in the periphery, and its action may be not due to inhibition of PG synthesis or release.