Hot spots of retinoic acid synthesis in the developing spinal cord.
Hot spots of retinoic acid synthesis in the developing spinal cord.
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DOI：
10.1073/pnas.91.15.7194
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发表时间：
1994-07
影响因子：
11.1
通讯作者：
P. McCaffery;U. C. Dräger
中科院分区：
文献类型：
--
作者：
P. McCaffery;U. C. Dräger
已知胚胎脊髓富含视黄酸，一些间接证据表明这种化合物的背腹浓度差异。然而，之前对背腹侧视黄酸水平的测量仅显示出微小的差异。通过显微解剖和生物测定技术相结合，我们比较了从早期胚胎到出生后小鼠脊髓沿着的视黄酸水平和视网膜醛脱氢酶水平。这两个参数的变化是平行的，表明区域视黄酸差异的主要原因是不同水平的视黄酸生成酶在发育中的脊髓。与以前的报告一致，我们观察到整体相当高的合成，随着年龄的增长而下降，在整个脊髓长度的大部分没有背腹侧差异。然而，在两个位置，腹侧合成超过背侧合成几个数量级。这些热点与肢体神经支配的起源共定位。它们在肢体神经支配的早期阶段最高，出生后慢慢消失。合成热点可能会产生局部视黄酸扩散晕，这可能会影响脊髓肢体区域神经元的存活，并可能促进发育肢体的神经支配。
The embryonic spinal cord is known to be rich in retinoic acid, and several indirect lines of evidence point to a dorsoventral concentration difference of this compound. Previous measurements of dorsoventral retinoic acid levels, however, showed only minor differences. By a combination of microdissection and bioassay techniques, we compared retinoic acid levels with retinaldehyde dehydrogenase levels along spinal cords from early embryonic to postnatal mice. Both parameters vary in parallel, indicating that the principal reason for regional retinoic acid differences in the developing spinal cord is different levels of retinoic acid-generating enzyme. Consistent with previous reports, we observed overall quite high synthesis, decreasing with age, and no dorsoventral difference throughout much of the spinal cord length. In two locations, however, ventral synthesis exceeds dorsal synthesis by several orders of magnitude. These hot spots colocalize with the origins of the limb innervations. They are highest during early stages of limb innervation and disappear slowly postnatally. The synthesis hot spots are likely to create local retinoic acid diffusion halos, which may influence the survival of neurons in the limb regions of the spinal cord and which probably promote innervation of the developing limbs.