Tomozawa Y, Appel S H
Brain Res. 1986 Dec 3;399(1):111-24. doi: 10.1016/0006-8993(86)90605-0.
Recent studies have suggested that diffusible factors released by neural target tissues enhance survival, growth, and differentiation of neurons within the central, as well as the peripheral, nervous system. In this report, we use catecholamine cytofluorescence to demonstrate that a soluble factor from the striatum produces a 4-fold increase in number of catecholamine cytofluorescent-positive dopaminergic neurons in dissociated mesencephalon cultures prepared from embryonic 14-day-old rats. The same soluble extract enhances the number of neurites per cell and the length of neurites, and also produces a greater than 3.5-fold stimulation of high affinity dopamine uptake into neurons. Such stimulation is significantly reduced following trypsin treatment. The trophic effects on dopaminergic neurons are maximal in extracts of the striatum, but are also found in extracts of the hippocampus-entorhinal cortex-amygdaloid nucleus and the cerebral cortex, although they are less in extracts of the cerebellum, negligible in the olfactory bulb, and absent in the liver. With molecular sieving chromatography, the soluble factors stimulating high affinity dopamine uptake are partially separable from the factors stimulating neuronal high affinity GABA uptake. The approximate molecular weight of the factors influencing dopaminergic neurons is 1500-2200 Da.
最近的研究表明，神经靶组织释放的可扩散因子可增强中枢神经系统和周围神经系统中神经元的存活、生长和分化。在本报告中，我们使用儿茶酚胺细胞荧光法来证明，来自纹状体的一种可溶性因子可使从14日龄胚胎大鼠制备的离体中脑培养物中儿茶酚胺细胞荧光阳性多巴胺能神经元的数量增加4倍。相同的可溶性提取物可增加每个细胞的神经突数量和神经突长度，还能使神经元对高亲和力多巴胺摄取的刺激增加3.5倍以上。胰蛋白酶处理后，这种刺激作用显著降低。对多巴胺能神经元的营养作用在纹状体提取物中最大，但在海马-内嗅皮质-杏仁核和大脑皮质提取物中也有发现，不过在小脑提取物中作用较小，在嗅球中可忽略不计，在肝脏中则不存在。通过分子筛色谱法，刺激高亲和力多巴胺摄取的可溶性因子与刺激神经元高亲和力GABA摄取的因子可部分分离。影响多巴胺能神经元的因子的近似分子量为1500 - 2200道尔顿。
