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

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。

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 Ca2+ 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.