Cheung H T, Nadakavukaren M J
Mech Ageing Dev. 1983 May;22(1):23-33. doi: 10.1016/0047-6374(83)90004-0.
The age-related changes in the cellularity (cells/gram of tissue) of the spleens and thymuses of Fischer F344 male rats were determined. A decline in the weight of the thymus with age was observed as previously reported by others. The decline was most drastic between 4 and 20 months of age. The spleen, however, increased in weight with age. The increase was almost linear between 4 and 30 months of age. Yet when the number of cells recovered from each organ as a function of age was determined, a decrease for both the thymus and the spleen was observed with increasing age. It was surprising to find that fewer cells were recovered from the spleens of old animals even though the weight of the spleen of the old animals was greater than the spleens from the younger animals. The ultrastructure of the splenic white pulp of rats ranging from 4 to 30 months of age was studied to determine the possible cause for the age-related decrease in cellularity of the spleen. The white pulp of the 4-month-old rats contained a large number of small lymphocytes, and the number of cells was found to decrease with increasing age. The 30-month-old animals had less than 20% the number of lymphocytes in the white pulp as the 4-month-old animals, and the white pulp exhibited an increased number of reticular cells and macrophages with enlarged cytoplasm. The decreased cellularity and increased structural disturbance might be significant in the age-related decline of spleen lymphocyte functions.
测定了Fischer F344雄性大鼠脾脏和胸腺细胞密度（每克组织中的细胞数）的年龄相关变化。如其他人之前报道的那样，观察到胸腺重量随年龄下降。这种下降在4至20个月龄之间最为显著。然而，脾脏重量随年龄增加。在4至30个月龄之间，这种增加几乎呈线性。然而，当确定从每个器官回收的细胞数量随年龄的变化时，发现胸腺和脾脏的细胞数量均随年龄增加而减少。令人惊讶的是，尽管老年动物的脾脏重量大于幼年动物的脾脏，但从老年动物脾脏中回收的细胞却更少。研究了4至30个月龄大鼠脾脏白髓的超微结构，以确定脾脏细胞密度与年龄相关下降的可能原因。4个月龄大鼠的白髓含有大量小淋巴细胞，且细胞数量随年龄增加而减少。30个月龄动物白髓中的淋巴细胞数量不到4个月龄动物的20%，并且白髓中网状细胞和巨噬细胞数量增加，细胞质增大。细胞密度降低和结构紊乱增加可能在脾脏淋巴细胞功能与年龄相关的衰退中具有重要意义。
