Objective To observe the influence of electroacupuncture(EA) on T cell immunologic function in the aged rats so as to reveal its underlying mechanism in anti-aging effect.Methods Fifty SD rats(half male and half female) were randomly divided into normal control(young rats).aging model(model)

EA group

immunosuppression(IS)

and EA+IS groups. Aging model(in the late 4 groups) was duplicated by subcutaneous injection of D-galactose for 40 days.Guanyuan(CV 4)and bilateral Zusanli(ST 36) were punctured and stimulated electrically(2 Hz.1 mA)

15 min every time

six times a week and for four weeks.IS model was induced by i.p.i.of Cytoxan(60 mg/kg) after 26 and 27 days' EA treatment.Splenetic T lymphocyte proliferation index was assayed by Methylthiazolyldiphenyl-tetrazolium bromide(MTT) chromatometry.IL-2/IL-2 receptor(R) expression level of T cells was measured by enzyme linked immunosorbent assay(ELISA).CD8

+

CD28+ CD28

+

-T cell subset fluorescence intensity was detected by flow cytometry.Results Compared with normal control group

the splenetic T lymphocyte proliferation index

IL-2 and IL-2R expression levels

and CD8+-T cell subset fluorescence intensity was detected by flow cytometry.Results Compared with normal control group

the splenetic T lymphocyte proliferation index

IL-2 and IL-2R expression levels

and CD8

+

CD28+ CD28

+

-T cell density in model and IS groups decreased significantly (P

<

0.01).In comparison with model group

the abovementioned indexes in EA and EA + IS groups increased significantly (P

<

0.01)

and those indexes levels of EA+IS group were also significantly higher than those in IS group(P

<

0.05

P

<

0.01).Comparison between EA and EA+IS groups showed that CD8+-T cell density in model and IS groups decreased significantly (P

<

0.01).In comparison with model group

the abovementioned indexes in EA and EA + IS groups increased significantly (P

<

0.01)

and those indexes levels of EA+IS group were also significantly higher than those in IS group(P

<

0.05

P

<

0.01).Comparison between EA and EA+IS groups showed that CD8

+

CD28+ CD28

+

T cell expression of the later group was significantly lower than that in EA group(P

<

0.05).No significant differences were found between EA and EA+IS groups in T cell proliferation rate and IL-2 and IL-2R expression levels(P

>

0.05).Conclusion EA of CV 4 and ST 36 induced upregulation of T cell proliferation and IL-2/IL-2R.and CD8+ T cell expression of the later group was significantly lower than that in EA group(P

<

0.05).No significant differences were found between EA and EA+IS groups in T cell proliferation rate and IL-2 and IL-2R expression levels(P

>

0.05).Conclusion EA of CV 4 and ST 36 induced upregulation of T cell proliferation and IL-2/IL-2R.and CD8

+

CD28+ CD28

+

-T cell may contribute to its antiaging and immuno-enhancement effects in the aged rats.