Inhibition Of Salicylate On Voltage-gated Sodium Channels In Rat Spiral Ganglion Neurons

Objective:To investigate the role of spiral ganglion neuron(SGN)'s voltage-gated sodium channels in the progress of hear loss induced by sodium salicylate,to discover the mechanism of sodium salicylate on the ionic channel level.Method:The whole-cell patch clamp recording technique was used to record I_Na,IV curse and others electrophysiological characteristics of the acutely dissociated spiral ganglion neuron isolated from rat,and detect the effects on these electrophysiological and pharmacological characteristics.Result:(1)The sodium current(I_Na)was inhibited by sodium salicylate in concentration-dependent manner(10μM-1000μM).The inhibition was reversible. (2)Whether applied sodium salicyalate,I_Nawould be activated on-60 mV and peaked on-10 mV.The voltage-gated property of I_Nawould not be affected by sodium salicylate.(3)The steady-state activation curse of I_Nahad no significant changed when was applying sodium salicylate 500μM.Their V_1/2were -35.74±1.58 and -38.03±2.69 mV and Sloap were 10.3±1.05 and 9.65±1.935 (n=5,P＜0.05).Conclusion:Our results suggest that sodium salicylate causes a reversible concentration-dependent blockade of I_Naand lead to a decreased action potential in SGN,which could be related to the mechanism of salicylate-induce hear loss.