Epidemiological studies on dietary habit and daily activity in the aged and study on anti-aging factors by using cellular immunity as an index

1.胸腺T细胞分化与成熟及维生素E：6周龄F344大鼠分别饲喂对照或高维生素E饲料，其中维生素E(α-生育酚烟酸酯)含量是对照饲料的10倍，共7周。高维生素E组大鼠胸腺细胞中的CD4+CD8-和CD4-CD8+T细胞比例均增加。饲喂高维生素E饲料的大鼠胸腺细胞产生IL-2增加，PGE_2减少。胸腺上皮细胞(TEC)功能也通过饲喂高维生素E饲料而增强。尤其是高维生素E饮食可显著增加未成熟T细胞与TEC的结合，这与ICAM的表达增加有关，但对胸腺皮质与髓质之间存在的巨噬细胞功能(负选择)无影响。这些结果表明，高维生素E饮食通过增加胸腺皮质TEC功能(阳性选择)和促进胸腺髓质突变T细胞的增殖来促进胸腺T细胞的分化和成熟。2.细胞免疫功能随增龄、维生素E和运动训练而降低：F344大鼠从年轻时(8周龄)开始饲喂对照组或高维生素E饮食12个月。然后对其脾细胞功能(有丝分裂)进行检测。结果表明，饲喂对照饲料的大鼠脾细胞的增殖在ConA或PHA的作用下降低，而喂高维生素E饲料的大鼠脾细胞的增殖明显增强，与8周龄幼鼠的增殖几乎相同。这与高维生素E饮食引起的脾巨噬细胞功能增强和脾淋巴细胞对有丝分裂原敏感性的增加有关。此外，运动训练还能改善随年龄增长而降低的细胞免疫功能。

1.T cell differentiation and maturation in thymus and vitamin E :Six weeks old, F344 rats were fed control or high vitamin E diet, which contained 10 times higher vitamin E (alpha-tocopherol nictonate) than control diet, for 7 weeks. Rats from the high vitamin E group showed the increases in the proportions of both CD4+CD8- and CD4-CD8+ T cells in their thymocytes. In adition, the increase of IL2 production and the decrease of PGE_2 were shown in thymocytes of rats fed the high vitamin E diet. Thymic epithelial cell (TEC) function was also increased by feeding of the high vitamin E diet. Especially, the binding of immature T cells to TEC was significantly increased by the high vitamin E diet, which was associated with the increased expression of ICAM.However, vitamin E had no effect on macrophage function (Negative selection) existing between thymic cortex and medulla. These results suggest that high vitamin E diet enhances T cell differentiation and maturation in thymus via both the increased TEC function (Positive selection) in thymic cortex and increased proliferation of muture T cells in thymic medulla.2.The decrease of cellular immunity with aging, vitamin E and exercise training :F344 rats were fed control or the high vitamin E diet for 12 months from young age (8 weeks old). Then, their splenocyte function (mitogenesis) was investigated. As a result, rats fed control diet showed the decreased proliferation of splenocytes with Con A or PHA.On the other hand, rats fed the high vitamin E diet showed a significant increase of splenocyte proliferation, which was almost the same as that of young rats (8 weeks old). This was associated with both the increase of splenic macrophage function and the increased susceptibility of splenic lymphocytes to mitogen by feeding high vitamin E diet. Furthermore, the decrease of cellular immunity with aging was also improved by exercise training.