论文部分内容阅读
目的观察银杏叶总黄酮(TFG)对交感神经节细胞迟慢兴奋性突触后电位(ls-EPSP)的影响并分析其作用的可能机制。方法细胞内记录技术和离体神经节灌流。结果豚鼠肠系膜下神经节(IMG)细胞静息电位为(-53·1±6·5)mV(n=54);重复电刺激(10V,1ms,20Hz,4s)与IMG相连的腹下神经,在IMG有61·1%(33/54)的细胞可诱发ls-EPSP,其电位的幅度与时程分别为(7·7±1·8)mV和(97·4±17·4)s(n=33);用TFG(100~500mg/L)灌流,其中有78·8%(26/33)细胞的ls-EPSP出现抑制,幅度与时程均表现降低和缩短,且表现一定的剂量依赖性;另有21·2%(7/33)的细胞无明显反应。由TFG引起的ls-EPSP抑制可被低钙/高镁Krebs液可逆性阻断,但不受胆碱或肾上腺素受体阻断剂影响;亦可被低钠(58mmol/L)、高钾(20mmol/L)的Krebs液和河豚毒(10μmol/L)所增强,并可被四乙基铵(1mmol/L)所减弱。结论TFG可不同程度抑制IMG内大多数细胞的ls-EPSP,其作用离子机制可能与Na+内流减弱和K+外流增强有关。
Objective To observe the effect of total flavonoids of ginkgo biloba leaves (TFG) on delayed excitatory postsynaptic potential (ls-EPSP) of sympathetic ganglion cells and analyze the possible mechanism of its action. Methods Intracellular recording techniques and isolated ganglionic perfusion. Results The resting potential of guinea pig inferior mesenteric ganglion (IMG) cells was (-53·1±6·5) mV (n=54); repeated electrical stimulation (10V, 1ms, 20Hz, 4s) of the inferior ventral nerve connected to IMG. In the IMG, 61.1% (33/54) of the cells induced ls-EPSP, and the magnitude and duration of the potential were (7·7±1·8) mV and (97·4±17·4), respectively. s (n=33); With TFG (100-500 mg/L) perfusion, 78.8% (26/33) of cells exhibited inhibition of ls-EPSP, and both amplitude and duration were decreased and shortened, and the performance was constant. Dose-dependent; another 21. 2% (7/33) of the cells did not respond significantly. Inhibition of ls-EPSP by TFG can be reversibly blocked by a low calcium/high magnesium Krebs solution, but not by choline or adrenergic receptor blockers; it can also be low sodium (58 mmol/L), high potassium. (20mmol/L) Krebs solution and tetrodotoxin (10μmol/L) were enhanced and could be weakened by tetraethylammonium (1mmol/L). Conclusion TFG can inhibit ls-EPSP of most cells in IMG to varying degrees, and its mechanism of action may be related to the reduction of Na+ influx and the enhancement of K+ efflux.