尼古丁对6-羟多巴胺诱导PC12细胞凋亡的拮抗作用

目的　探讨尼古丁对 6 羟多巴胺 (6 OHDA)诱导PC1 2细胞凋亡的拮抗作用及其与烟碱受体的关系。方法　用 6 OHDA诱导大鼠肾上腺嗜铬细胞瘤细胞株PC1 2细胞凋亡的细胞模型 ;用MTT、二乙酸荧光素活细胞染色、流式细胞仪和DNA琼脂糖凝胶电泳等方法检测PC1 2细胞的凋亡 ;用尼古丁及N型和M型受体拮抗剂预处理 ,观察尼古丁的拮抗作用及其与受体的关系。结果　尼古丁可明显拮抗 6 OHDA(50 μmol·L-1 )诱导PC1 2细胞凋亡 ,呈钟型浓度效应关系 ,1 0 μmol·L-1 尼古丁的拮抗作用最强。用 1 0 μmol·L-1 尼古丁预处理PC1 2细胞 2h可明显降低 6 OHDA诱导的细胞凋亡。用 1 0 μmol·L-1 六甲溴胺阻断烟碱受体 ,可取消尼古丁对 6 OHDA诱导细胞凋亡的拮抗作用 ;但用阿托品阻断M型胆碱受体 ,对尼古丁的拮抗作用则无明显影响。结论　尼古丁对 6 OHDA诱导的PC1 2细胞凋亡有明显的拮抗作用 ,这种作用由烟碱受体所介导。

Antagonism of nicotine on PC12 cell apoptosis induced by 6-hydroxidopamine

AIM To explore whether nicotine antagonises the PC12 cell apoptosis induced by 6-hydroxydopamine(6-OHDA). METHODS MTT assay, fluorescein diacetate nuclear staining, flow-cytometry and DNA fragmentation electrophoresis in agarose gel were used for detecting PC12 cell apoptosis. RESULTS Apoptosis of the cultured PC12 cells induced by 6-OHDA 50 μmol•L^-1 was antagonisted by pretreating with nicotine (0.1, 1, 10, 100, 1000 μmol•L^-1) for 2 h, in a bell-shape concentration dependent manner with the strongest protective effect at 10 μmol•L^-1. The antagonistic effect of nicotine was completely blocked by hexamethoniun 10 μmol•L^-1, but not atropine 0.1 μmol•L^-1, suggested that this effect be mediated by nicotinic receptor. CONCLUSION Nicotine may prevent PC12 cell from apoptosis induced by 6-OHDA, which is mediated by nicotine receptor.