大鼠5－羟色胺能神经元相关营养因子的实验研究

Study on Neurotrophic Factor for Tryptaminergic Neruons in Rats

本文从５，７－ＤＨＴ损伤的海马中制备了一种提取液，并测定了提取液对小脑内移植的胚胎５－ＨＴ神经细胞存活和生长的影响，结果显示１：２００烯释的提取液能显著增加神经细胞的存活率、神经纤维密度和５－羟色胺及５－羟哚乙酸的水平，同时移植区也明显增大，但１：１稀释的提取液对移植的中缝核神经细胞促进作用不明显。实验结果表明：①去５－ＨＴ神经的海马提取液含有某种海马释放的物质，属于损伤诱发的内源性物质。②该营养物质可直接或间接地促进５－ＨＴ神经元的生长和促进５－ＨＴ神经递质的合成与代谢。③高浓度提取液中可能存在某种抑制５－ＨＴ神经元生长的因子。

he 5-HT-denervated hippocampus was found to be a favorable encironment for the growth of grafted 5-HT, but not for norepinephrinergic neurons.In this study,we have extracted a trophic factor in the denervatedhippocampus with hypotonic solution in high-speed supernatant fraction.The trophic extract was assayed in aunique experimantal paradigm-test the growth of grafted 5-HT neurons in the cerebellum, which rpceives theleast 5-HT innervation,and where grafted 5-HT neurons have seldom survived.The diluted trophic extract(1:200)produced a dramatic increase in(a)the survival rate.(b)the 5-HT fiber-density,and(c)the 5-HT and 5-hydroxyindoleacetic acid levels of grafted 5-HT neurons in the eerebellum.In addition,Nissl-counterstainingshowed that the size of the grafted raphe also apparently increased.The concentrated trophic extract(1:1) didnot increase the survival rate of the grafted raphe neurons,These results indicate that(a)the supernatant in the5-HT-denervated hippocampus contains a potent neurotrophic factor to 5-HT neurons,(b)which can eitherdirectly or indirectly also support 5-HT raphe neurous,and(c)possibly an inhibitory factor is present which isdetrimental to 5-HT neurons in high concentration.