铃蟾肽、P物质受体脱敏对迟慢兴奋性突触后电位的影响

The effect of seperate desensitization of substance P and bombesin receptor on ls-EPSP in neurons of guinea pig inferior mesenteric ganglion

目的 :探讨豚鼠肠系膜下神经节 (IMG)细胞铃蟾肽 (bombesin ,Bom)、P物质 (substanceP ,SP)受体间相互作用及对迟慢兴奋性突触后电位 (ls EPSP)的影响。方法 :离体细胞内记录 ,并观察细胞的去极化、ls EPSP的时程、幅度。结果 :SP受体脱敏可使SP敏感细胞的ls EPSP阻抑 ,但对Bom去极化无影响 ;Bom受体脱敏可使Bom敏感细胞的ls EPSP阻抑 ,但对SP受体去极化无影响。结论 :Bom、SP可通过各自的突触后膜受体形成ls EPSP ,无交互脱敏现象。

Objective:To investigate the effects of desensitization of substance P and bombesin(Bom) receptor on ls EPSP in neurons of guinea pig inferior mesenteric ganglion.Methods:Intracellular recordings were made from neurons of the isolated guinea pig IMG.Results:SP receptor desensitization can abolish or markedly attenuate ls EPSP in SP sensitive neurons,but had not any effects on Bom mediated depolarization;By contrast,Bom receptor desensitization can also abolish or markedly attenuate ls EPSP in Bom sensitive neurons,but had no effect on SP mediated depolarization.Conclusions:Bom and substance P can produce ls EPSP via respective receptor on the membrane of synapse,and no cross desensitization between receptors. [