Hayashi M, Edgar D, Thoenen H
Dev Biol. 1985 Mar;108(1):49-55. doi: 10.1016/0012-1606(85)90008-9.
The effects of chronic nerve growth factor administration on the development of neuropeptides in the embryonic chick peripheral nervous system were quantitated by radioimmunoassays. Starting at embryonic Day 3.5, daily doses of 20 micrograms of nerve growth factor (NGF) increased the substance P content of lumbosacral spinal sensory ganglia at all ages studied (Days 10-14), while having no effect on substance P levels of thoracic sensory ganglia. In contrast, the contents of somatostatin were increased in both thoracic and lumbosacral ganglia, but only at comparatively late time points (Day 14). Nerve growth factor administration was also found to decrease the somatostatin contents of lumbosacral paravertebral sympathetic ganglia at early time points (Day 8) while increasing levels at later stages (Day 14), thus acting to accelerate the normally occurring developmental changes in level of this peptide. These changes were shown to be specific for somatostatin by demonstrating that NGF increased tyrosine hydroxylase levels in sympathetic neurons at Day 8, and had no effect on sympathetic vasoactive intestinal polypeptide levels at Day 14. It has been concluded that exogenous NGF does not simply act to increase or prolong the expression of neuron-specific phenotypes in the chick, but rather its action is time and location dependent to accelerate development.
通过放射免疫测定法对慢性给予神经生长因子对胚胎期鸡外周神经系统中神经肽发育的影响进行了定量研究。从胚胎第3.5天开始，每日给予20微克神经生长因子（NGF），在所有研究的年龄段（第10 - 14天）均增加了腰骶部脊髓感觉神经节中P物质的含量，而对胸段感觉神经节中P物质的水平没有影响。相比之下，生长抑素的含量在胸段和腰骶部神经节中均增加，但仅在相对较晚的时间点（第14天）出现。还发现给予神经生长因子在早期时间点（第8天）会降低腰骶部椎旁交感神经节中生长抑素的含量，而在后期阶段（第14天）会增加其水平，从而起到加速该肽水平正常发生的发育变化的作用。通过证明神经生长因子在第8天增加交感神经元中酪氨酸羟化酶的水平，且在第14天对交感神经血管活性肠肽水平没有影响，表明这些变化对生长抑素具有特异性。得出的结论是，外源性神经生长因子并非简单地作用于增加或延长鸡中神经元特异性表型的表达，而是其作用具有时间和位置依赖性，以加速发育。
