P物质对大鼠星状神经节细胞的除极化

Depolarization Induced by Substance P on Rat Stellate Ganglion Neurons

关键词:  P物质  星状神经节  细胞生物电记录

Key words:  substance P  stellate ganglion  intracellular recording

摘要:

应用细胞内生物电记录技术,观察神经肽P物质(SP)对大鼠星状神经节细胞的影响。SP在1μmol~10μmol或更高的浓度范围内,供试35个细胞,有28个细胞发生膜除极反应。用低钙(0.25mm)或用含河豚毒素(TTX,1μmol)克氏液灌流神经节,不影响SP引起的除极反应的幅度和时程。SP引起除极反应的同时常伴有膜电阻增大。当膜电位增大时,除极化反应幅度变小,反转电位为-80mV至-100mV。研究表明,SP对部分星状神经节细胞具有兴奋作用,使通过这些细胞的信息传递增强;SP对细胞膜的除极作用是由于其引起细胞膜钾导降低所致。

Abstract:

The effects of neuropeptide substance P(SP) on the neurons of the isolated stellate ganglia of the rat were investigated by means of intracellular recording techniques.At the concentration of 1 μm to 10 μm,SP-caused a low,monophersic depolarization in 28 out of 35 cells tested,low Ca²⁺ or tetrodotoxin (TTX) -containing Kreb's solution did not cause any significant change of the amplitude or duration of SP-induced depolarization.SP-induced depolarization was often associated with an increase in membrane resistance.Generally,the response was reversed on membrane potential of -80 mV to -100 mV.It is concluded that SP is excitatory to stellate ganglionic neurons and serves to augment impulse transmission through the neurons.These findings also suggest that a reduction of membrane K⁺ conductance may underline the depolarization action of SP.