Agrawal S G, Evans R H
Br J Pharmacol. 1986 Feb;87(2):345-55. doi: 10.1111/j.1476-5381.1986.tb10823.x.
Dorsal roots (L3-L7) isolated from immature (1-9 day old) rats were depolarized selectively by kainate (1-100 microM). L-Glutamate (25-100 microM), but not L-aspartate, mimicked the action of kainate. N-methylaspartate had no activity on these preparations and quisqualate was thirty times less active than kainate. Depolarizations evoked by L-glutamate (100-1000 microM) faded rapidly in the presence of L-glutamate. Depolarizations evoked by kainate were depressed during the fade induced by L-glutamate. Certain electrically evoked C-fibre volleys in dorsal roots or leg nerves of rats at any age were selectively depressed or abolished in the presence of kainate. The effect of kainate was more selective than that of gamma-aminobutyric acid or capsaicin. Prolonged treatment of dorsal roots with kainate did not appear to be deleterious to C-fibres. It is suggested that certain primary afferent C-fibres possess kainate receptors which may be activated physiologically by L-glutamate released at their central terminations.
从未成熟（1 - 9日龄）大鼠分离出的背根神经（L3 - L7）可被谷氨酸钾（1 - 100微摩尔）选择性去极化。L - 谷氨酸（25 - 100微摩尔）可模拟谷氨酸钾的作用，但L - 天冬氨酸则不能。N - 甲基 - D - 天冬氨酸对这些标本无活性，喹啉酸的活性比谷氨酸钾低30倍。在L - 谷氨酸存在的情况下，由L - 谷氨酸（100 - 1000微摩尔）诱发的去极化迅速消退。在L - 谷氨酸诱发的消退过程中，谷氨酸钾诱发的去极化受到抑制。在任何年龄的大鼠背根神经或腿部神经中，某些电诱发的C纤维群落在谷氨酸钾存在时会被选择性抑制或消除。谷氨酸钾的作用比γ - 氨基丁酸或辣椒素更具选择性。用谷氨酸钾对背根神经进行长时间处理似乎对C纤维无害。提示某些初级传入C纤维具有谷氨酸钾受体，这些受体可能在其中枢终末释放的L - 谷氨酸作用下被生理性激活。
