[Effect of Electroacupuncture Intervention at Different Time-points on Levels of HSP 70, MDA, SOD and GSH-PX of Liver in Rats with Simulated Weightlessness].

Objective: To observe the effect of acupuncture intervention at different time-points on the activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), the content of malonaldehyde (MDA) and expression of heat shock protein 70 (HSP 70) of liver tissue in rats with simulated weightlessness, so as to explore its mechanism underlying improvement of liver injury in rats with simulated weightlessness.
Methods: Twenty male Wistar rats were randomly divided into control group, model group, pre-acupuncture group and EA group, 5 rats in each. The model of simulated weightlessness was established by tail suspension for 4 week. One week before the tail suspension, the rats in the pre-acupuncture group were treated with electroacupuncture (EA) at "Shenshu" (BL 23), "Pishu"(BL 20) and "Sanyinjiao" (SP 6) for 30 min before treatment, once a day for 7 days. The rats in the EA group received tail suspension and acupuncture intervention at the same time. EA was applied for 30 min per treatment, once every other day for 14 times. Immunohistochemical staining was used to assay the expression of HSP 70 in the liver tissue. The activities of SOD and GSH-PX and content of MDA in liver tissues were examined by means of colourimetric method. Results Compared with the control group,the expression of HSP 70 and the content of MDA in the liver tissue were increased significantly (P < 0.01), and the activity of SOD and GSH-PX was notably reduced (P < 0.05) in the model group. Compared with the model group, the content of HSP 70 was significantly reduced in the pre-acupuncture group (P < 0.01). There were no significant changes in the levels of SOD, GSH-PX, MDA and HSP 70 in the EA group (P > 0.05). In comparison with the pre-acupuncture group, the activity of GSH-PX was lower (P < 0.05) and the content of MDA was higher (P < 0.05) in the EA group.
Conclusion: EA-pretreatment can suppress the increase of liver HSP 70 immunoactivity in rats with simulated weightlessness, being likely to improve the antioxidant ability of liver.