内吗啡肽-1对成年大鼠脊髓胶状质内突触传递的抑制作用强于内吗啡肽-2(英文)  

ENDOMORPHIN-1 IS MORE POTENT THAN ENDOMORPHIN-2 IN INHIBITION OF SYNAPTIC TRANSMISSION IN SUBSTANTIA GELATINOSA OF ADULT RAT SPINAL CORD

作　　者：冷冬妮[1] 冯宇鹏[1] 李云庆[1] 

机构地区：[1]第四军医大学解剖学教研室暨梁金求琚脑研究中心,西安710032

出　　处：《神经解剖学杂志》2005年第3期269-275,共7页Chinese Journal of Neuroanatomy

基　　金：国家自然科学基金(No.39970239,30370458);国家重点基础研究规划(G1999054004)资助项目

摘　　要：本实验采用全细胞电压钳记录方法,研究了内吗啡肽1(EM1)和内吗啡肽2(EM2)对脊髓背角胶状质神经元突触传递的抑制性作用。EM1(1μmol/L)和EM2(1μmol/L)都能够显著抑制微小兴奋性突触后电流(mEPSCs)和微小抑制性突触后电流(mIPSCs)的频率而不改变其幅值。这种抑制作用能被μ受体选择性拮抗剂βfunaltrexamine(βFNA,10μmol/L)阻断。值得注意的是,EM1对mEPSCs和mIPSCs的频率的抑制作用强于EM2。上述结果提示在脊髓胶状质,内吗啡肽通过激活突触前膜上的μ受体,抑制兴奋性和抑制性的突触传递;与EM2相比,EM1可能是脊髓水平的更强效的内源性镇痛剂。Effects of endomorphin-1 (EM-1) and endomorphin-2 (EM-2) on synaptic transmission were investigated on neurons in substantia gelatinosa (SG) of the spinal dorsal horn by whole-cell voltage clamp recording. Both EM-1 (1 μmol/L) and EM-2 (1 μmol/L) remarkably reduced the frequency but not the amplitude of miniature excitatory postsynaptic currents (mEPSCs) and miniature inhibitory postsynaptic currents (mIPSCs). These effects were antagonized by β-funaltrexamine (β-FNA, 10 μmol/L), a selective μ-opioid receptor antagonist. Noticeably, EM-1 showed higher potency in decreasing the frequency of mEPSCs and mIPSCs than that of EM-2. These results indicate that EMs suppress both excitatory and inhibitory synaptic transmission by activating presynaptic μ-opioid receptors in the SG and EM-1, compared with EM-2, might be a more potent endogenous analgesic at the spinal cord level.

关 键 词：内吗啡肽-1 成年大鼠 脊髓 突触 抑制作用 内吗啡肽-2 全细胞电压钳记录法 Μ受体 

分 类 号：R33[医药卫生—人体生理学]