Ichikawa M, Maeda T, Handa J
Department of Neurosurgery, Shiga University of Medical Science, Shiga, Japan.
Childs Nerv Syst. 1997 Nov-Dec;13(11-12):578-83. doi: 10.1007/s003810050143.
Polyamines have various roles in cortical development. We examined the ontogenic changes in ornithine decarboxylase (ODC), the rate-limiting enzyme of polyamine biosynthesis, in cerebral cortices of normal and hydrocephalic rats. Both biochemical and immunohistochemical examinations revealed increased ODC protein and enzyme activity during the perinatal period. Apical dendrites of developing neuroblasts migrating from the superficial layer of cortical plate showed intense ODC immunoreactivity. Once they had settled at their final destination, ODC immunoreactivity weakened. Both ODC immunoreactivity and enzyme activity reached very low levels after completion of layer formation of cortex. The enzyme activity of ODC in hydrocephalic cortices exceeded that in normal cortex during the perinatal periods. ODC was rather overexpressed, but no characteristic distribution was observed in the hydrocephalic cortex. These findings indicate the participation of polyamines in the cortical development, especially in the layer formation. The overexpression of ODC in hydrocephalus appears to promote development despite increased hydrostatic pressure.
多胺在皮质发育中具有多种作用。我们研究了正常和脑积水大鼠大脑皮质中鸟氨酸脱羧酶（ODC）的个体发育变化，ODC是多胺生物合成的限速酶。生化和免疫组织化学检查均显示，围产期ODC蛋白和酶活性增加。从皮质板表层迁移的发育中神经母细胞的顶端树突显示出强烈的ODC免疫反应性。一旦它们定居在最终目的地，ODC免疫反应性就会减弱。在皮质层形成完成后，ODC免疫反应性和酶活性均降至非常低的水平。围产期脑积水皮质中ODC的酶活性超过正常皮质。ODC在脑积水皮质中相当过度表达，但未观察到特征性分布。这些发现表明多胺参与了皮质发育，尤其是在层形成过程中。脑积水时ODC的过度表达似乎在静水压力增加的情况下仍能促进发育。
