CHARACTERISTICS　OF　ACTIONPOTENTIAL　AND　THEIR　UNDERLYING　OUTWARD　CURRENTS　IN　MAMMALIAN　TASTE　RECEPTOR　CELLS

作     者：陈玉社 

出 版 物：《Journal of Pharmaceutical Analysis》 (药物分析学报（英文版）)

年 卷 期：1995年第9卷第2期

页      面：189-189页

学科分类：1001[医学-基础医学(可授医学、理学学位)] 100101[医学-人体解剖与组织胚胎学] 10[医学] 

主　　题：taste patch-clamps action potential potassium currents forskolin 

摘      要：Many rat taste receptor cells conduct action potentials(APs).APs had a mean threshold of -35 mV(n=95 cells)and a spike height of 52mV above threshold in current clamp(hold= -80mV).Aps could be classified into two significantly different (P0.001) groups-fast,with short half-time durations and large outward currents (mean1.3 ms and 2.7nA),and slow,with long duration and small outward currents(mean9.2ms and 0. 29nA).AP upstrokes were conducted by TTX-sensitive sodium currents whereas the downstroke by TEA-blockable outward currents. Voltage dependent analysis of outward current separated transient and sustained *** transient component was specifically blocked by 4-AP(1mmol/L).A calcium-dependent outward component was also revealed modulating voltage and external calcium *** fast recovery phase of the AP appears related the sustained outward current whereas the after hyperpolarization(AHP) was blocked by 4AP suggesting a significant contribution of the transient *** (FSK),which elevates cAMP,reversibly blocked the majority of the sustained current without influencing the transient. FSK greatly exaggerated the AHP without changing the spike height or duration. These data suggest that several components of the outward current contribute specifically to the gustatory AP and that the AP may be modulated by cyclic nucleotides.