Sugisaki T, Beamer W G, Noguchi T
Department of Physiology, Toho University School of Medicine, Tokyo, Japan.
Int J Dev Neurosci. 1992 Oct;10(5):453-8. doi: 10.1016/0736-5748(92)90036-y.
To determine whether somatomedin has a direct action on cerebral development instead of an indirect action of a growth hormone, we examined the central nervous system of the pygmy mouse (pg), a mutant with normal somatomedin activity. Our findings are: (A) the weights of the pg/pg cerebrum and cerebellum weighted were significantly less than those of the normal controls (pg/+), 14 and 15% less, respectively; (B) the total DNA content was reduced by 17% in the cerebrum and cerebellum of the pg/pg mouse; (C) the total RNA content was reduced in the cerebrum and cerebellum, proportional to the reduction in DNA; (D) CNPase activity was reduced selectively in the cerebrum of the pg/pg mouse by 25%; and (E) the pg/pg mice exhibited a strikingly reduced level of activity with an indistinct diurnal periodicity. Therefore, the present findings suggest that the action of somatomedin on the proliferation and maturation of glial cells might be a necessary precondition to myelin formation.
为了确定生长调节素对大脑发育是否具有直接作用，而非生长激素的间接作用，我们研究了侏儒小鼠（pg）的中枢神经系统，该小鼠是一种生长调节素活性正常的突变体。我们的研究结果如下：（A）pg/pg小鼠大脑和小脑的重量显著低于正常对照（pg/+），分别低14%和15%；（B）pg/pg小鼠大脑和小脑的总DNA含量降低了17%；（C）大脑和小脑中的总RNA含量降低，与DNA的降低成比例；（D）pg/pg小鼠大脑中的CNPase活性选择性降低了25%；（E）pg/pg小鼠的活动水平显著降低，昼夜节律不明显。因此，目前的研究结果表明，生长调节素对神经胶质细胞增殖和成熟的作用可能是髓鞘形成的必要前提条件。
