梓醇促大鼠大脑皮质神经元轴突生长的离体研究

Study of catalpol promoting axonal growth for cultured cortical neurons from rats

目的：观察梓醇对原代培养的新生SD大鼠皮质神经元生存活性及轴突生长的影响。方法：新生24h内SD大鼠大脑皮质神经元原代培养6d后，分为空白组、终浓度分别为0．25，0．5，1．0，2．5，5．0mg·mL^-1梓醇干预组和终浓度为1．0mg·mL^-1胞磷胆碱阳性药物对照组。药物干预48h后，观察细胞生长情况，用NF-200免疫组化染色鉴定神经元，MTT法检测神经元生存活性，测微尺测量神经元轴突长度。结果：梓醇终浓度在1～5mg·mL^-1时，可明显促进神经元轴突生长，2．5mg·mL^-1时作用最强；梓醇各浓度组神经元生存活性与空白组和胞磷胆碱组差异无显著性。结论：梓醇能明显促进皮质神经元轴突生长，但对其生存活性无显著影响。

Objective： To explore the effects of different concentration of catalpol on the cell survival and axonal growth of cortical neurons cultured in vitro from 24 h newly born rat. Method ： Primary cultured cortical neurons from 24 h newly born rat were dissociated and cultured. The different concentration of catalpol and 1 mg . mL^- 1 citicoline were added to the culture plates for 48 h, and the final of catalpol concentration were 0. 25, 0. 5, 1, 2. 5, 5 mg . mL^- 1, respectively. The cortical neuron was identified by NF-200 antigen and its survival activity detected by MTT assay. The axonal growth of cultured cortical neuron were observed by inverted microscopy with micrometer. Result： Immunocytochemistry demonstrated more than 95% of the primary cultured cortical neurons were positive for NF-200 antigen, which indicated the cultured cells were neurons. Neurons survived growing on the concentration of 0. 25, 0. 5, 1, 2. 5, 5 mg . mL^-1. Compared with blank and 1 mg . mL^-1 citicoline group, neurons survival rates were not statistical significant difference. However, it demonstrated that catalpol significantly promoted axonal growth from 1-5 mg . mL^-1 （P 〈 0. 05 ）. Interestedly, compared with the dose of 2. 5 mg . mL^- 1, axonal growth was shorter at the dose of 5 mg . mL^-1, and 2. 5 mg . mL^-1 catalpol showed the strongest promotion effect. Conclusion： The catalpol can enhance cortical neuron axonal growth, but not promote cortical neuron survival.