缓激肽对大鼠背根神经节分离神经元ATP激活电流的调制作用

在新鲜分离大鼠背根神经节（ＤＲＧ）的５６个细胞标本上,应用全细胞膜片箝技术进行记录。胞外加缓激肽（ＢＫ,１０＾－６￣１０＾－４ｍｏｌ／Ｌ）引坊的ＤＲＧ细胞膜反应结果如下：（１）７１．４％的细胞为内向电流,其电流反应的幅值具有明显的浓度信赖性;（２）１２．５％的细胞为外向电流;（３）１６．１％的细胞未引起可检测的膜反应,单独给予ＡＴＰ（１０＾－６￣１０＾－３ｍｏｌ／Ｌ）在大多数受栓细胞（５４／５６）

Modulation of bradykinin on ATP-activated currents in isolated rat DRG neurons

Modulation of bradykinin (BK) on ATP-activated membrane currents in the isolated rat dorsal root ganglion (DRG) neurons was investigated using whole-cell patch-clamp technique. In 56 neurons examined, BK (10(-6)-10(-4) mol/L)-induced responses were as follows: (1) inward current (40/56); (2) outward current (7/56); (3) no responses (9/56). In the majority of the neurons examined, ATP (10(-6)-10(-3) mol/L) activated a concentration-dependent inward current with obvious desensitization. ATP-activated current was potentiated markedly by preapplication of BK. The enhancement of BK was dependent on the concentration of BK and ATP. It was found that BK potentiated the peak value of ATP-activated currents predominately while the steady state value was not affected obviously. The onset of BK potentiation of ATP-activated currents needed preincubation of BK at least for 30 s and the time of the enhancement lasted over 20 min. The results suggest that BK may play a role in the facilitation of the excitatory effect of ATP on primary sensory neurons.