Effects of Panax notoginseng saponins on the fast-excitatory postsynaptic potential in rat stellate ganglion
- VernacularTitle:大鼠星状神经节快兴奋性突触后电位变化与三七总皂甙的影响
- Author:
Yan ZHOU
;
Lei TIAN
;
Ming MO
- Publication Type:Journal Article
- From:
Chinese Journal of Tissue Engineering Research
2007;11(25):5044-5046
- CountryChina
- Language:Chinese
-
Abstract:
BACKGROUND: Panax notoginseng saponins (PNS) could significantly improve the learning and memory ability of rats, but its influence to peripheral nervous system still needs further investigation.OBJECTIVE: To observe the effects of PNS on the fast-excitatory postsynaptic potential (f-EPSP) in stellate ganglion (SG) of rats.DESIGN: Observation and controlled trial.SETTING: Pharmacological Laboratory of Guangxi Medical University.MATERIALS: The experiment was carried out at the Pharmacological Laboratory of the Experimental Center of Guangxi Medical University from January 2005 to February 2006. Thirty healthy male SD rats of clean grade and (220±20) g, provided by the Experimental Animal Center of Guangxi Medical University; SEN-7203 digital three track strip stimulator, microelectrode amplifier (MEZ8301, Japan NIHON KOHDEN COMPANY); glass microelectrode puller, and microelectrode manipulator, both the products of Narishige Company, Japan; PNS, provided by Kunming Jacobson Pharmaceutical Co., Ltd, and acetylchloride chline (Ach), the product of Sigma, U.S.A.METHODS: After the animals were executed acutely, their chest wall was opened to isolate SG rapidly under microscope, which was transferred to the perfusion chamber, and fixed with wire needles after peeling the connective tissue membrane. The ganglia were perfused continuously with the mixture of volume fraction 0.95 O2 and 0.05 CO2 plus Krebs solution with pH (7.4±0.05). Meanwhile, 0.08-0.16 g/L PNS was employed to perfuse and culture SG.①The glass microelectrode filled with 3 mmol/L KCI was used to puncture the isolated SG and record the amplitude and duration of depolarizing reaction of postsynaptic membrane.②PNS with the maximum concentration of 0.16 g/L, which could inhibit the f-EPSPs, was perfused to observe the effect of PNS on the amplitude and duration of depolarizing reaction of postsynaptic membrane induced by exogenous Ach (1 mmol/L, 1 minute).③PNS with the maximum concentration of 0.16 g/L, which could inhibit the f-EPSPs, was perfused to observe the effect of PNS on membrane resistance and membrane potential.MAIN OUTCOME MEASURES:①Amplitude of depolarizing reaction of postsynaptic membrane; ②Effect of PNS on the amplitude and duration of depolarizing reaction of postsynaptic membrane induced by exogenous Ach, and membrane resistance and membrane potential.RESULTS: Thirty rats were involved in the result analysis. ①PNS ranged 0.08 to 0.16 g/L could reversibly depress the f-EPSPs amplitude of, or change the forward active potential into f-EPSP; the higher the concentration of PNS, the more obvious the inhibition was. The depression appeared in 3-10 minutes after PNS perfusion, and the effect reached the peak at 0.16 g/L; f-EPSP was decreased evidently in 3 to 4 minutes. The inhibition nearly recovered to the control level after washing the ganglia with Krebs solution for 15 to 20 minutes. ②Effect of PNS on exogenous ACh-induced depolarization: The amplitude and duration of the Ach-induced depolarization did not significantly change before and 5 minutes after 0.16 g/L PNS perfusion [before: (15.5±2.4) mV, (256.1±21.5) seconds; after: (14.3±1.9) mV, (228.6±24.5) seconds, P＞0.05].③Effects of PNS on membrane potential and membrane resistance: The mean membrane potential and membrane resistance were not significantly changed after PNS perfusion [before:-(55.5±12.1) mV, (53.9±5.1) MΩ; after: -(54.3±10.4) mV, (55.1±4.8)MΩ, P＞0.05].CONCLUSION: PNS could reversibly depress the fast-excitatory postsynaptic potential in stellate ganglion of rats by presynaptic mechanism.
