Effects of emodin on synaptic transmission in rat hippocampal CA1 pyramidal neurons in vitro
Effects of emodin on synaptic transmission in rat hippocampal CA1 pyramidal neurons in vitro
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DOI：
10.1016/j.neuropharm.2005.02.003
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发表时间：
2005-07-01
影响因子：
4.7
通讯作者：
Akasu, T
中科院分区：
文献类型：
--
作者：
Gu, JW;Hasuo, H;Akasu, T
大黄提取物对脑损伤后的神经具有保护作用，但这种保护作用的机制尚不清楚。本研究验证了大黄提取液干扰脑神经元谷氨酸释放从而降低谷氨酸兴奋性毒性的假说。为此，大黄素是从唐古特大黄中提取的一种蒽醌衍生物。前男友。BALF对体外培养的大鼠海马区CA1区锥体神经元突触传递的影响。大黄素(0.3~30mM)浸浴可抑制兴奋性突触后电位(EPSP)。大黄素可显著增加EPSP的双脉冲易化(PPF)。大黄素不改变谷氨酸受体拮抗剂(DNQX和AP5)所记录的单突触抑制性突触后电位(IPSP)。大黄素可降低迷你EPSP的频率，但不降低其幅度。大黄素对EPSP的抑制作用可被腺苷A(1)受体拮抗剂8-CPT或腺苷脱氨酶阻断。这些结果提示，大黄素通过激活大鼠海马CA1区腺苷A(1)受体，减少Schaffer侧支/连合末梢谷氨酸的释放，从而抑制EPSP；大黄提取物的神经保护作用可能与降低谷氨酸的兴奋性毒性有关。(C)2005爱思唯尔有限公司。保留所有权利。
Rhubarb extracts provide neuroprotection after brain injury, but the mechanism of this protective effect is not known. The present study tests the hypothesis that rhubarb extracts,interfere with the release of glutamate by brain neurons and, therefore, reduce glutamate excitotoxicity. To this end, the effects of emodin, an anthraquinone derivative extracted from Rheum tanguticum Maxim. Ex. Balf, on the synaptic transmission of CA1 pyramidal neurons in rat hippocampus were studied in vitro. The excitatory postsynaptic potential (EPSP) was depressed by bath-application of emodin (0.3-30 mu M). Paired-pulse facilitation (PPF) of the EPSP was significantly increased by emodin. The monosynaptic inhibitory postsynaptic potential (IPSP) recorded in the presence of glutamate receptor antagonists (DNQX and AP5) was not altered by emodin. Emodin decreased the frequency, but not the amplitude, of the miniature EPSP (mEPSP). The inhibition of the EPSP induced by emodin was blocked by either 8-CPT, an adenosine A(1) receptor antagonist, or by adenosine deaminase. These results suggest that emodin inhibits the EPSP by decreasing the release of glutamate from Schaffer collateral/commissural terminals via the activation of adenosine A(1) receptors in rat hippocampal CA1 area and that the neuroprotective effects of rhubarb extracts may result from decreased glutamate excitotoxicity. (c) 2005 Elsevier Ltd. All rights reserved.