【摘要】 目的　研究丘脑中央下核 (Sm)内微量注射吗啡对大鼠福尔马林试验诱发的腰段脊髓背角c fos蛋白表达的抑制效应。方法　用免疫组化的方法观察c fos样免疫反应神经元在脊髓背角的表达与分布。结果　Sm内微量注射吗啡 (5 μg ,0 .5 μL)可以明显抑制大鼠后肢跖部皮下注射福尔马林诱发脊髓背角的c fos蛋白表达 ,c fos阳性神经元数为 (2 6 .5 8± 1.79)个 ,与注射生理盐水相比 [(6 2 .0 9± 14 .5 9)个 ],明显减少 (P <0 .0 0 1) ,并且这种抑制效应可被Sm内微量注射阿片受体拮抗剂纳洛酮 (1.0 μg ,0 .5 μL)所翻转 ,其c fos阳性神经元数为 (5 5 .5 0± 9.81)个 ,与单独注射吗啡相比差异显著 (P <0 .0 5 ) ,但与注射生理盐水相比 ,无显著差异 (P >0 .0 5 )。结论　阿片肽及其受体可能参与Sm介导的下行抗伤害感受效应更多还原

【Abstract】 Objective To identify the effect of microinjection of morphine into the nucleus submedius (Sm) on the formalin-induced c-fos protein expression of neurons in the spinal dorsal horn. Methods Immunohistochemical technique was employed in the c-fos protein expression. Results Microinjection of morphine (5 μg, 0.5 μL) into the Sm markedly depressed the c-fos protein expression of neurons in the spinal dorsal horn evoked by formalin injected subcutaneously. The number (26.58±1.79) of c-fos-like neurons after morphine administration lessened compared with that (62.09±14.59) of saline control (P<0.001), and this effect could be blocked by administration (55.50±9.81) of the opioid receptor antagonist naloxone (1.0μg, 0.5μL)) into the same site (P<0.05). Conclusion Opioid peptide and its receptors in the Sm may be involved in the descending antinociception.更多还原