Enhancement of rat trigeminal ganglion neuron responses to piperine in a low-pH environment and block by capsazepine
Enhancement of rat trigeminal ganglion neuron responses to piperine in a low-pH environment and block by capsazepine
复制标题
DOI：
10.1016/s0006-8993(97)00305-3
复制
发表时间：
1997-06-27
期刊：
影响因子：
2.9
通讯作者：
Baumann, TK
中科院分区：
文献类型：
--
作者：
Martenson, ME;Arguelles, JH;Baumann, TK
三叉神经和脊神经节神经元在酸性环境中对刺激性辣椒素的反应都表现出强烈的增强作用。目前的研究表明，质子和胡椒碱，另一种香草素刺激物之间也有很强的相互作用。研究了质子与胡椒碱相互作用的机理。在培养的成年大鼠三叉神经节（TG）神经元上进行全细胞膜片钳记录，在其静息膜电位（-60 mV）附近进行电压钳位。苦参碱（10 μ M）引起持续的净内向电流与膜电导的增加或减少。当质子和胡椒碱共同应用时，在胡椒碱敏感的TG神经元中诱发的膜电流远远超过对单独应用的两种刺激的反应的代数和。辣椒平阻断TG神经元胡椒碱在生理和酸性pH值的反应。在辣椒平的存在下，胡椒碱和质子的混合物的反应类似于单独应用的低pH刺激的反应。辣椒平对持续质子诱导电流无影响。这些研究结果表明，质子增强胡椒碱电流通过改变香草酸受体/通道复合物或增加空间钳的长度常数。(C)1997年Elsevier Science B.V.
Both trigeminal and spinal ganglion neurons show a strong potentiation of responses to the irritant capsaicin in an acidic environment. The present study revealed that there is also a strong interaction between protons and piperine, another vanilloid irritant. We studied the mechanism of the interaction between protons and piperine. Whole-cell patch clamp recordings were performed on cultured adult rat trigeminal ganglion (TG) neurons voltage-clamped near their resting membrane potential (-60 mV). Piperine (10 mu M) caused a sustained net inward current associated with either an increase or decrease in membrane conductance. When protons and piperine were co-applied, the membrane currents evoked in piperine-sensitive TG neurons far exceeded the algebraic sum of the responses to the two stimuli applied in isolation. Capsazepine blocked the response of TG neurons to piperine at both physiological and acidic pH. in the presence of capsazepine, responses to the mixture of piperine and protons resembled the response to the low pH stimulus applied alone. Capsazepine had no effect on the sustained proton-induced current. These findings suggest that protons enhance the piperine current by altering the vanilloid receptor/channel complex or increasing the length constant of the space clamp. (C) 1997 Elsevier Science B.V.