成年小鼠氯胺酮慢性中毒后脑细胞凋亡

Apoptosis in Adult Mouse Brain after Chronic Poisoning of Ketamine

目的研究不同持续时间和剂量下氯胺酮慢性中毒对成年小鼠脑细胞凋亡发生的影响。方法氯胺酮按不同剂量(4、10、20、30mg/kg)每周2次于成年小鼠尾静脉注射,建立小鼠氯胺酮滥用慢性中毒模型,氯胺酮连续注射1、2、4、8、12周后处死。采用透射电镜进行细胞凋亡的定性检测,以Caspase-3免疫荧光染色法和脱氧核糖核苷酸末端转移酶介导的缺口末端标记法(terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling,TUNEL)定量检测凋亡细胞数,推断凋亡发生的时间,并统计分析实验结果。结果氯胺酮染毒1周后,在透射电镜下见到脑组织海马及纹状体区域有明显的神经元凋亡,并持续至8周后;染毒1周可见Caspase-3高表达,4周后呈持续低水平表达;染毒1周后可见TUNEL阳性细胞较对照组明显增加,4周时仍处于高水平表达。结论氯胺酮尾静脉注射可致成年小鼠神经元凋亡。

Objective To study the effect of chronic poisoning of ketamine on brain cell apoptosis in adult mouse under different duration and doses. Methods The mouse model of chronic poisoning of ketamine was established on adult mouse by tail vein injection of ketamine twice every week with different doses （4, 10, 20 and 30 m g/kg）. The mice were sacrificed after continuous injection of ketamine of 1, 2, 4, 8 and 12 weeks. The qualitative assessment of apoptosis was made by transmission electron microscope and the quantitative assessment was made by Caspase-3 im m umofluorescence staining method and terminal deoxynucleotidyl transferase-mediated dU TP nick end labeling （TUNEL ） to estimate the time point of apoptosis. All the experimental results were statistically analyzed. Results The neuron apoptosis was ob-served in hippocam pus and corpus striatum by transmission electron microscope one week after adminis-tration, and continued for eight weeks. High level of Caspase-3 expression was observed one week after administration, but with a lowlevel expression after 4 weeks. The num ber of TUNEL positive cells ob-viously increased one week after administration and maintained in ahigh num ber at 4 weeks. Conclu-sion Ketamine by tail vein injection could induce neuron apoptosis in adult mouse.