右美托咪定对咪达唑仑所致神经干细胞增殖、分化和凋亡改变的影响

目的 研究咪达唑仑对神经干细胞(neural stem cells,NSCs)增殖、分化及凋亡的毒性作用及右美托咪定(dexmedetomidine,Dex)能否缓解咪达唑仑的神经毒性作用. 方法 分离培养孕14～15 d大鼠胚胎大脑皮质NSCs,将NSCs接种于培养板中,培养24 h后,将其按照完全随机分组法分为3组:对照组(C组)、咪达唑仑组(M组)、Dex联合咪达唑仑组(M+D组).分别采用咪达唑仑、Dex联合咪达唑仑处理培养的第一、二代NSCs 24 h,采用噻唑蓝3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide,MTT)]比色法检测细胞活力,溴脱氧尿苷(5-bromo-2-deoxyuridine,BrdU)掺入法检测细胞增殖,免疫细胞化学法观察NSCs分化情况,原位末端标记法(terminal dUTP nick-end labeling,TUNEL)检测细胞凋亡. 结果 与对照组比较,咪达唑仑干预NSCs 24 h可降低细胞活力(对照组0.214±0.006,咪达唑仑组0.187±0.002)、减少细胞增殖(对照组(35.7±1.0)％,咪达唑仑组(27.6±1.0)％]、增加细胞凋亡对照组(5.7±0.8)％,咪达唑仑组(7.8±1.1)％](P＜0.01),但对NSCs分化没有显著影响(P＞0.05);与咪达唑仑处理比较,Dex联合咪达唑仑干预NSCs 24 h,可增加细胞活力M+D组0.233±0.007]和细胞增殖M+D组(35.7±1.1)％]、减少细胞凋亡M+D组(5.3±1.0)％](P＜0.01),但对NSCs向神经元和星形胶质细胞分化无明显影响(P＞0.05). 结论 Dex可缓解咪达唑仑抑制NSCs增殖、促进细胞凋亡的作用,但不影响其向神经元和星形胶质细胞方向分化.

The effect of dexmedetomidine on the changes induced by midazolam in proliferation,differentiation and apoptosis of neural stem cells in vitro

Objective To investigate the effects of dexmedetomidine (Dex) on the proliferation,differentiation and apoptosis of neural stem cells (NSCs) of rats induced by midazolam in vitro.Methods NSCs were isolated from the cerebral cortex of rat embryos on embryonic day 14-15,and P1-P2 cells were treated with midazolam,Dex combined with midazolam 24 h,with the untreated cells served as control.Cell viability was detected by MTT assay.Cell proliferation was evaluated by 5-bromo-2-deoxyuridine (BrdU) incorporation.Immunocytochemical staining was used to study the differentiation of NSCs.Cell apoptosis was assessed by TUNEL.Results Treatment with midazolam significantly inhibited cell viability C group (0.214±0.006),M group (0.187±0.002)] and proliferationC group(35.7±1.0)％,Mid group (27.6％±1.0％)],increased the cell apoptosisC group (5.7±0.8)％,Mid group(7.8±1.1)％](P＜0.01),but did not affect the differentiation of NSCs(P＞0.05).Compared with M group,the combination of Dex and midazolam significantly improved cell viability(0.233±0.007) and proliferation(35.7±1.1)％,and decreased the cell apoptosis(5.3±1.0)％ (P＜0.01).There was no significant difference in the differentiation of NSCs between the M group and the M+D group (P＞0.05).Conclusions Treatment with Dex improves the decreased NSCs proliferation and increased cell apoptosis induced by midazolam,but has no significant influence on differentiation of NSCs into neurons and astrocytes.