Caron P C, Unsworth B R
Mech Ageing Dev. 1978 Sep;8(3):181-95. doi: 10.1016/0047-6374(78)90017-9.
Protein, DNA and thymidine kinase levels were assayed during development and aging in the mouse cerebellum. A roughly parallel increase in protein and DNA content occurred from birth, reaching a plateau at 18 days; these adult levels increased by 30% in the 23 month-old cerebellum. Thymidine kinase activity reached a maximum at 6 postnatal days, then decreased steadily to reach, at 18 days, the low level that was maintained in the adult. The thymidine kinase synthesized in the aged cerebellum differed from that in the neonate by having (i) an increased specific activity, (ii) a faster migrating species upon electrophoresis, (iii) an inhibition by dCTP, and (iv) a lower affinity for the substrate thymidine (higher Km). Mathematical calculations indicated the appearance of a larger number of smaller sized cells in the aged cerebellum, when compared with the young adult. Histological analysis established that the newly synthesized cells were localized in the molecular layer of the old cerebellum. It appears that senescence in the mouse cerebellum may be associated with an increased synthesis of glial cells.
在小鼠小脑发育和衰老过程中对蛋白质、DNA和胸苷激酶水平进行了测定。从出生起，蛋白质和DNA含量大致呈平行增加，在18天时达到稳定状态；在23月龄的小脑中，这些成年水平增加了30%。胸苷激酶活性在出生后6天达到最大值，然后稳步下降，在18天时达到成年期维持的低水平。老年小脑合成的胸苷激酶与新生儿的不同之处在于：（i）比活性增加；（ii）电泳时迁移速度更快的物种；（iii）受dCTP抑制；（iv）对底物胸苷的亲和力较低（较高的Km）。数学计算表明，与年轻成年小鼠相比，老年小脑中出现了大量较小尺寸的细胞。组织学分析证实，新合成的细胞位于老年小脑的分子层中。看来小鼠小脑的衰老可能与神经胶质细胞合成增加有关。
