Basso A, Piantanelli L, Rossolini G, Roth G S
Gerontological Research Department, Italian National Research Centers on Aging, Ancona, Italy.
J Gerontol A Biol Sci Med Sci. 1998 Mar;53(2):B111-6. doi: 10.1093/gerona/53a.2.b111.
We previously observed in vivo that a neonatal thymus grafted into old mice can correct age-related changes such as occurrence of hepatocyte tetraploid nuclei and impaired isoproterenol-induced DNA synthesis in submandibular glands. The aim of the present paper was to study the influence of age and thymus on basal and beta-adrenergic-stimulated DNA synthesis using primary cultures of mouse hepatocytes. In the absence of any adrenergic agents, cells from young mice show peak DNA synthesis between 36 and 48 h; old mice show a similar time course, but the peak is significantly reduced statistically. The main result is represented by the behavior of hepatocytes from old thymus-grafted mice, which recover the levels of [3H]-thymidine incorporation toward young-like values. Grafted animals also show a correction of total DNA content that is increased in old mice. The addition of isoproterenol does not modify the DNA synthetic pattern, whereas the antagonist propranolol causes a slight but statistically significant decrease.
我们之前在体内观察到，将新生小鼠的胸腺移植到老年小鼠体内，可以纠正与年龄相关的变化，如肝细胞四倍体核的出现以及异丙肾上腺素诱导的下颌下腺DNA合成受损。本文的目的是利用小鼠原代肝细胞培养物研究年龄和胸腺对基础及β-肾上腺素能刺激的DNA合成的影响。在没有任何肾上腺素能药物的情况下，年轻小鼠的细胞在36至48小时之间显示出DNA合成峰值；老年小鼠显示出类似的时间进程，但峰值在统计学上显著降低。主要结果表现为来自移植了胸腺的老年小鼠的肝细胞的行为，其[3H]-胸苷掺入水平恢复到类似年轻小鼠的水平。移植动物的总DNA含量也得到了纠正，老年小鼠的总DNA含量增加。加入异丙肾上腺素不会改变DNA合成模式，而拮抗剂普萘洛尔则会导致轻微但在统计学上显著的下降。
