P物质对大鼠星状神经节细胞的影响

应用细胞内生物电记录方法，观察神经肽Ｐ物质（ＳＰ）对大鼠星状神经节能细胞的影响，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

Effect of Substance P on Rat Stellate Ganglion Neurones

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.