银杏内酯B对豚鼠腹腔神经节神经元Fast-EPSP的抑制效应

应用细胞内记录技术,观察并分析了银杏内酯B(GB)对豚鼠(Cavia porcellus)离体腹腔神经节(CG)神经元快兴奋性突触后电位(fast-EPSP)的影响及可能机制.用4×10-6mol/L的GB灌流CG,fast-EPSP的幅值均明显降低,与对照组相比有显著性差异(n=12,P<0.05);用低Ca2 /高Mg2 Krebs液灌流,fastEPSP被完全抑制(n=3);用高Ca2 Krebs液灌流,fast-EPSP幅度则增大(n=12,P<0.05),而用4×10-6mol/L GB与高Ca2 Krebs液联合灌流,fast-EPSP幅度则减小(n=12,P<0.05).结果提示,GB对CG神经元fast-EPSP的抑制效应可能与减少或抑制CG神经元的外Ca2 内流有关.

The Inhibitory Effect of Ginkgolide B on Fast-EPSP in the Celiac Ganglion Neurons of Guinea Pig

The present study was carried out to determine the regulation of ginkgolide B(GB)on fast-excitatory postsynaptic potential(fast-EPSP)in the neurons of celiac ganglion(CG)and the mechanisms involved in the GB-induced responses.Intracellular recording was employed to measure the fast-EPSP in the neurons of CG freshly isolated from Guinea Pigs(Cavia porcellus).We found that perfusion of GB(4×10^-6 mol/L)significantly decreased the amplitude of fast-EPSP in the CG neurons(n=12,P<0.05).The fast-EPSP was completely inhibited by a low Ca ²⁺/high Mg ²⁺ Krebs solution(n=3),but significantly enhanced by a high Ca ²⁺ Krebs solution(n=12,P<0.05),suggesting a contribution of extracellular Ca ²⁺ to the generation of the fast-EPSP.The high Ca ²⁺ Krebs solution-induced augmentation of the fast-EPSP was significantly attenuated by GB(n=12,P<0.05).These results indicate that GB negatively regulates fast-EPSP in CG neurons in Guinea pigs through an inhibition on external Ca ²⁺ entry.