抄録
The quantitative analysis of nociceptive reaction produced by i.m. injection of some algesic derivatives of penicillin and cephalosporin was carried out with rabbits. A half ml of the drug solution was injected into the antebrachial muscle of rabbits, and a characteristic behavior was scored by measuring the length of time during which the animals lifted a forelimb of the injected side. Since the response to 25% carbenicillin solution was reduced either by premedication with 1 or 3 mg morphine/kg i. v.in a dose dependent manner or by utilizing 0.5% lidocaine solution as a solvent for carbenicillin, the observed behavior may be regarded as the manifestation of pain experience in the animals. Carbenicillin, sulbenicillin and cephalothin produced the pronounced pain response, while cephazolin was relatively less noxious in rabbits. Timoxicillin, a new wide-spectrum penicillin, was the least painful among the sodium salt of antibiotics tested. Cephaloridine, which is not a sodium salt but a betaine form, showed no detectable pain response. The present results are consistent with many clinical experiences with respect to pain produced by these intramuscular remedies. The method described here seems useful for screening the compounds which are presumed to possess algesic activity.
