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.