期刊文献+

Inhibitory effects of microinjection of morphine into thalamic nucleus submedius on ipsilateral paw bee venom-induced inflammatory pain in the rat

Inhibitory effects of microinjection of morphine into thalamic nucleus submedius on ipsilateral paw bee venom-induced inflammatory pain in the rat
下载PDF
导出
摘要 Objective To examine whether microinjection of morphine into the rat thalamic nucleus submedius (Sm) could depress the bee venom (BV)-induced nociceptive behaviours. Methods In inflammatory pain model induced by BV subcutaneous injection into rat unilateral hind paw,the inhibitory effects of morphine microinjection into thalamic nucleus submedius (Sm) on the spontaneous nociceptive behavior,heat hyperalgesia and tactile allodynia,and the influence of naloxone on the morphine effects were observed in the rat. Results A single dose of morphine (5.0 μg,0.5 μL) applied into the Sm ipsilateral to the BV injected paw significantly depressed the spontaneous paw flinching response. Morphine also significantly increased the heat paw withdrawal latencies in the bilateral hind paw and the tactile paw withdrawal threshold in the ipsilateral hind paw 2 hours after BV injection. All these depressive effects could be effectively antagonized by pre-treatment with the opioid receptor antagonist naloxone (1.0 μg,0.5 μL) in the Sm 5min prior to morphine administration. Naloxone alone injected to the Sm had no effect on the BV-induced nociceptive behavior. Conclusion These results suggest that Sm is involved in opioid receptor-mediated anti-nociception in the rat with the BV-induced inflammatory pain. Together with results from previous studies,it is likely that this effect is produced by activation of the Sm-ventrolateral orbital cortex-periaqueductal gray pathway,leading to activation of the brainstem descending inhibitory system and depression of the nociceptive inputs at the spinal cord level. Objective To examine whether microinjection of morphine into the rat thalamic nucleus submedius (Sm) could depress the bee venom (BV)-induced nociceptive behaviours. Methods In inflammatory pain model induced by BV subcutaneous injection into rat unilateral hind paw,the inhibitory effects of morphine microinjection into thalamic nucleus submedius (Sm) on the spontaneous nociceptive behavior,heat hyperalgesia and tactile allodynia,and the influence of naloxone on the morphine effects were observed in the rat. Results A single dose of morphine (5.0 μg,0.5 μL) applied into the Sm ipsilateral to the BV injected paw significantly depressed the spontaneous paw flinching response. Morphine also significantly increased the heat paw withdrawal latencies in the bilateral hind paw and the tactile paw withdrawal threshold in the ipsilateral hind paw 2 hours after BV injection. All these depressive effects could be effectively antagonized by pre-treatment with the opioid receptor antagonist naloxone (1.0 μg,0.5 μL) in the Sm 5min prior to morphine administration. Naloxone alone injected to the Sm had no effect on the BV-induced nociceptive behavior. Conclusion These results suggest that Sm is involved in opioid receptor-mediated anti-nociception in the rat with the BV-induced inflammatory pain. Together with results from previous studies,it is likely that this effect is produced by activation of the Sm-ventrolateral orbital cortex-periaqueductal gray pathway,leading to activation of the brainstem descending inhibitory system and depression of the nociceptive inputs at the spinal cord level.
出处 《Journal of Pharmaceutical Analysis》 SCIE CAS 2009年第2期71-77,共7页 药物分析学报(英文版)
基金 supported by the National Natural Science Foundation of China (No.30270453 30570592)
关键词 nucleus submedius MORPHINE HYPERALGESIA ALLODYNIA bee venom model RAT nucleus submedius morphine hyperalgesia allodynia bee venom model rat
  • 相关文献

参考文献1

共引文献1

  • 1ZHANG Xu Institute of Neuroscience,State Key Laboratory of Neuroscience,Shanghai Institutes for Biological Sciences,Chinese Academy of Sciences,Shanghai 200031,China.Pain research in China[J].Science China(Life Sciences),2010,53(3):356-362. 被引量:2

相关作者

内容加载中请稍等...

相关机构

内容加载中请稍等...

相关主题

内容加载中请稍等...

浏览历史

内容加载中请稍等...
;
使用帮助 返回顶部