PERIPHERAL ANALGESIC ACTION OF CLONIDINE - MEDIATION BY RELEASE OF ENDOGENOUS ENKEPHALIN-LIKE SUBSTANCES
PERIPHERAL ANALGESIC ACTION OF CLONIDINE - MEDIATION BY RELEASE OF ENDOGENOUS ENKEPHALIN-LIKE SUBSTANCES
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DOI：
10.1016/0014-2999(88)90296-8
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发表时间：
1988-02-09
影响因子：
5
通讯作者：
FERREIRA, SH
中科院分区：
文献类型：
--
作者：
NAKAMURA, M;FERREIRA, SH
Clonidine analgesia was tested on the hyperalgesia induced by intraplantar injection of prostaglandin E2 or carrageenin. The antinociceptive effect of clonidine was dose-dependent and was abolished by local administration of the selective .alpha.2-adrenoceptor blocker, yohimbine or of the opioid antagonists naloxone or quaternary nalorphine. St-91, a clonidine analog which does not cross the blood-brain barrier also promoted significant antinociception. Repeated administration of drugs possessing a central mechanism of analgesic action leads to the development of tolerance in this test. Significant analgesic tolerance was observed following repeated (5 days) morphine (8 mg/kg) or high doses of clonidine (0.5 mg/kg). In contrast, no tolerance was detected to the analgesic effect of low doses of clonidine (0.15 mg/kg) or of St-91 (0.5 mg/kg). These results suggest that, in addition, to its central analgesic action, clonidine can induce peripheral antinociception by an .alpha.2-adrenoceptor-mediated local release of enkephalin-like substances.
