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.
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(+) -T cell subset fluorescence intensity was detected by flow cytometry.
Compared with normal control group, the splenetic T lymphocyte proliferation index, IL-2 and IL-2R expression levels, and CD8+ 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+ CD2+ 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)
EA of CV 4 and ST 36 induced upregulation of T cell proliferation and IL-2/IL-2R, and CD8+ CD(+)28 -T cell may contribute to its antiaging and immuno-enhancement effects in the aged rats.