中文摘要：

目的 研究μ-和δ-阿片受体在介导丘脑中央下核（Sm）内阿片诱发的抗伤害感受效应中的作用。方法 用自动检测系统记录大鼠爪底皮下注射福尔马林诱发的伤害性行为，观察Sm内微量注射吗啡和选择性μ-和δ-阿片受体拮抗剂对伤害性行为的效应。结果 吗啡（31mmol／L，0．5μL）明显抑制福尔马林诱发的伤害性行为，这种效应可被μ-阿片受体拮抗剂β—funaltrexamine（β-FNA，0．4mmol／L，0．5μL）和naloxonazine（0．8mmol／L，0．5μL）阻断，部分地被δ-受体拮抗剂naltrindole（0．4mmol／L，0．5μL）阻断。结论 Sm内注射吗啡诱发的抗伤害感受效应主要由μ-阿片受体介导，部分地由δ-受体介导。

英文摘要：

Objective To investigate whether the μ- and δ- opioid receptors were involved in mediating the antinociceptive effect of opioid injection into the nucleus submedius （Sm）. Methods Nociceptive behavior produced by subcutaneous injection of formalin （65 mmol/L, 50 μL） into the hind paw of the rat was assessed quantitatively using an automated movement detection system. The effects of morphine and selective μ- and δ- opioid receptor antagonists microinjected unilaterally into the Sm were determined in the awake rats. Results Morphine （31 mmol/L, 0. 5μL） depressed the nociceptive behavior elicited by formalin, and this effect was antagonized completely by the selective μ-receptor antagonist β-funaltrexamine （β-FNA, 0. 4 mmol/L, 0. 5 μL） and naloxonazine （0.8 mmol/L, 0.5μL）, and partly by the δ-receptor antagonist naltrindole （0.4 mmol/L, 0.5μL）. Administration of morphine into thalamic regions more than 0. 5 mm dorsal to the Sm had no effect on the nociceptive behavior. Conclusion Antinociceptive effects produced by opioid acting on Sm neurons are mediated mainly by μ-opioid receptors, and partly by δ-receptors.