Quisqualate and L-glutamate inhibit retinal horizontal-cell responses to kainate.
Quisqualate and L-glutamate inhibit retinal horizontal-cell responses to kainate.
复制标题
使君子酸和L-谷氨酸抑制视网膜水平细胞对红藻氨酸的反应。
DOI：
10.1073/pnas.82.6.1837
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发表时间：
1985
影响因子：
11.1
通讯作者：
J. Neyton
中科院分区：
文献类型：
--
作者：
A. Ishida;J. Neyton
使用膜片钳方法的全细胞记录配置，在离体金鱼水平细胞的电压钳下分析由 L-谷氨酸和相关激动剂使君子酸盐和红藻氨酸引起的电流 [Hamill, O.P., Marty, A., Neher, E., Sakmann, B. & Sigworth, F. J. (1981) Pflügers Arch. 391、85-100]。这些电流是由于阳离子电导增加而产生的，并且在反转电势（约等于 0 mV）和表观基元电导（2-3 pS）方面彼此无法区分。每种激动剂产生的噪声增加的功率密度谱通过具有相似截止频率（tau 1 约等于 5 毫秒，tau 2 约等于 1 毫秒）的两条洛伦兹曲线之和进行拟合，但这些成分的相对功率对于使君子酸盐和谷氨酸与红藻氨酸不同。此外，对高剂量的使君子酸盐或谷氨酸的反应迅速减弱，而对红藻氨酸的反应却没有。最后，使君子酸和谷氨酸对红藻氨酸反应产生抑制作用，这似乎是不具有竞争性的。在我们的制剂中，红藻氨酸、使君子氨酸和谷氨酸似乎激活的通道与其他制剂中 N-甲基-D-天冬氨酸激活的通道不同。君子兰酸盐和谷氨酸盐的至少一些作用似乎是由红藻氨酸结合的受体介导的。
Currents elicited by L-glutamate and the related agonists quisqualate and kainate were analyzed under voltage clamp in isolated goldfish horizontal cells, using the whole-cell recording configuration of the patch-clamp method [Hamill, O.P., Marty, A., Neher, E., Sakmann, B. & Sigworth, F. J. (1981) Pflügers Arch. 391, 85-100]. These currents resulted from an increase in cationic conductance and were indistinguishable from one another in terms of reversal potential (approximately equal to 0 mV) and apparent elementary conductance (2-3 pS). The power-density spectra of the noise increases produced by each agonist were fit by the sum of two Lorentzian curves having similar cutoff frequencies (tau 1 approximately equal to 5 msec, tau 2 approximately equal to 1 msec), but the relative power of these components were different for quisqualate and glutamate than for kainate. Moreover, the responses to high doses of either quisqualate or glutamate rapidly faded, whereas the responses to kainate did not. Finally, quisqualate and glutamate produced an inhibition of responses to kainate which appeared to be uncompetitive. Kainate, quisqualate, and in our preparation, glutamate appear to activate channels different than those activated by N-methyl-D-aspartate in other preparations. At least some of the effects of quisqualate and glutamate appear to be mediated by receptors bound by kainate.