P物质对大鼠星状神经节细胞的影响

Effect of Substance P on Rat Stellate Ganglion Neurones

关键词:  P物质  交感神经节  星状神经节细胞  细胞内生物电记录

Key words:  substance P  sympathetic ganglion  stellate ganglion neurone  intracellular recording

摘要:

应用细胞内生物电记录方法,观察神经肽P物质(SP)对大鼠星状神经节细胞的影响,用灌流或用加压向细胞周围施加SP可使部分细胞发生膜除极反应。用低钙或用含河豚毒素克氏液灌流神经节,并不影响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直接兴奋作用。并且,SP对细胞膜的除极作用是由于其引起细胞膜钾导降低所至。

Abstract:

Intracellular recordings were made from neurones of the isolated rat stellate ganglia. Substance P (SP) applied by superfusion or by pressure ejection elicited a slow depolarization in portion of stellate ganglion cells studied in vitro. The depolarization which persisted in a low Ca²⁺ solution or the solution containing TTX, was often associated with a increase in neuronal input resistance, and the response was reduced by membrane hyperpolarization and reversed their polarities between -80 mV and 100 mV. Our results suggest that SP is excitatory to stellate ganglion cells directly, and a reduction of membrane K⁺ conductance constitutes the primary ionic mechanism underlying the depolarizing action of SP.