Effect Of Electroacupuncture At "Zusanli" Points On Hemorrhagic Shock And Vagal Electric Activity

Part One Effects of Electroacupuncture at "Zusanli" Points of Hemorrhagic Shock in RatsObjective To observe the effects of electroacupuncture at "Zusanli" points in a rat model of experimental hemorrhagic shock.Methods 75 SD male rats(220±20g) were randomly divided into five groups, including Sham group, hemorrhagic shock group(Hem group), electroacupuncture at "Zusanli"group(EA group), electroacupuncture at non-acupoints group(non-acupoints group) and bilateral cervical vagotomy group(VGX group). Anesthetized rats were subjected to hemorrhagic shock or sham surgical procedures. Hemorrhagic shock model was induced by intermittent withdrawing of blood until the mean arterial pressure(MAP) maintained in the range of 25 to 30 mmHg for 5 minutes. Then "Zusanli" points were electroacupunctured by constant voltage pulses.The effects of electroacupuncture at "Zusanli" points on MAP, survival condition, levels of arterial blood-gas, lactic acid concentration, drying/wet (D/W) and the histopathology chang of lung were observed.Results Electroacupuncture at "Zusanli" points not only efficiently reversed the hypotension , improved the survival, but also quickly reverted the hypoxemia, hypercapnia and metabolic acidosis, decreased the blood lactic acid concentration and the D/W of lung in shock animals. At the same time the lung histopathology showed that electroacupuncture could improve the congestion and edema condition, and relieve the infiltration of inflammatory cells into interstitium. However, when the animals were subjected to bilateral cervical vagotomy, the protective effects of electroacupuncture at "Zusanli" points disappeared..Conclusion The present data show that electroacupuncture at "Zusanli" points can significantly reverses the hemorrhagic shock, and the protective effect depends on the vagus nerve integrity.Part TwoEffect of Electroacupuncture at "Zusanli" Points on VagalElectric ActivityObjective To investigate the changes of vagus nerve electric activity after electroacupuncture at "Zusanli" points.Methods 30 SD male rats(220±20g) were randomly divided into 3 groups, including control group, electroacupuncture at "Zusanli" group(EA group), and electroacupuncture at non-acupoints group (non-acupoints group). After the anesthetized animals were subjected to bilateral cervical vagus nerve segregation and ligation, one side of vagus nerve was placed on bipolar platinum electrodes at random and covered with mineral oil. Signals from the electrodes were amplified by an amplifier module (Input Impendance 1000 MV; EMG100A ; Mengtai Technology, China), passed through a band-pass filter (100-1000 Hz), and filtered nerve activity was recorded by an acquisition system (BL-4201, Biology Function Experimental Systems, Mengtai Technology, China). Efferent vagus nerve activity was recorded for 50min following electroacupuncture(3V, 2~4Hz, 30min).Results Both efferent and afferent vagal activity of control group and non-acupoints group didn't chang during the experiment time. About 7.5 minutes later, the animals were subjected to electroacupuncture at "Zusanli" points, both the frequency and the peak values of efferent vagal electric activity induced by the bipolar platinum electrodes increased significantly. However, these didn't happen in the afferent.Conclusion Electroacupuncture at "Zusanli" points increases activity of efferent vagus nerve, but doesn't influence the afferent activity.