关键词: 维甲酸, 分化, MAP2

Abstract: Objective To study the condition of pheochromocytoma cells(PC12 cells) differentiated into neuron-like cells induced by retinoic acid (RA) and to observe the lengh of neurite and max diameter and the expression of MAP2 in PC12 cells during their differentiation into neuron-like cells. Methods There were seven groups : 0.1,0.3,0.5,1.0,2.0 and 5.0 mg•L^-1RA groups and control group which contained 10% fetal calf serum.PC12 cells were exposed to RA with different concentrations for 72 h and the lengh of neurite and max diameter of PC12 cells were observed at 24,48,and 72 h respectively. The expression of MAP2 was detected by immunocytochemistry after PC12 cells were exposed to RA for 72 h.Results The number of MAP2 positive cells was significantly increased in 0.3,0.5,1.0,2.0 mg•L^-1RA groups compared with control group and the most significant concentration was 1.0 mg•L^-1（P<0.05）.The length of total primary neurite and max diameter of PC12 cells in 0.3,0.5,1.0,2.0 mg•L^-1RA groups were obviously longer and bigger than those in control group and the most significant concentration also was 1.0 mg•L^-1（P<0.01）.But the number and the lengh of neurite were fewer and shorter when PC12 cells were exposed to 2.0 mg•L^-1RA　 than that of 1.0 mg•L^-1 RA.There were a lot of black particles in PC12 cells and cells became smaller and aging when they were exposed to 2.0 mg•L^-1RA　 for 7 d. Conclusion PC12 cells could differentiate into neuron-like in vitro induced by RA,and RA could enhance the outgrowth of neurite and multiplication of max diameter of the differentiated PC12 cells.1.0 mg•L^-1 is 　the optimal concentration in which RA could induce PC12 cells to differentiate into neuron-like cells.

Key words: retinoic acid, differentiation, MAP2