[Effect of electroacupuncture of "Hegu" (LI 4)-"Taichong" (LR 3) on colonic nitric oxide synthase and glutathione peroxidase activity and nitric oxide content in depression rats].

Objective: To observe the effect of electroacupuncture (EA) on the activity of inducible nitric oxide synthase (iNOS), glutathione peroxidase (GSH-Px) and the content of nitric oxide (NO) in colon tissue of depression rats, so as to reveal its mechanism in protecting colonic tissue under depression.

Methods: Forty male SD rats were equally randomized into normal, model, medication and EA groups. Depression model was established by using chronic unpredictable mild stress stimulation (forced ice-water swimming, electric shock, tail-clamping, etc) combined with lonely raising for 21 days. At the same time of modeling, Fluoxetine (1.8 mg/kg, intragastric perfusion) was given to the rats of medication group, once daily for 21 days. EA (1.5-2 Hz, 1-3 mA) was applied to bilateral "Hegu" (LI 4) and "Taichong" (LR 3) for 20 min, once daily for 21 days. The activity of iNOS, GSH-Px and the content of NO in colon tissue were detected by ultraviolet spectrophotometer method.

Results: In comparison with normal control group, iNOS activity and NO content in colon tissue increased significantly (P<0.05), and GSH-Px activity decreased considerably (P<0.05) in model group. Whereas compared with model group, iNOS activity and NO content decreased significantly (P<0.05), and GSH-Px activity increased significantly in EA and medication groups. No significant differences were found between EA group and medication group in these 3 indexes (P>0.05).

Conclusion: EA of "Hegu" (LI 4) and "Taichong" (LR 3) can reduce stress induced increase of both iNOS activity and NO content, and decrease of GSH-Px activity in colon tissue in depression rats, which may contribute to its effect in protecting the digestive tract from injury under depression.