Objective: To investigate the roles of chloramphenicol (CAP) preconditioning in the oxidative respiratory function of cerebral mitochondria in rats exposed to acute hypoxia during acute hypoxia by observing the change...Objective: To investigate the roles of chloramphenicol (CAP) preconditioning in the oxidative respiratory function of cerebral mitochondria in rats exposed to acute hypoxia during acute hypoxia by observing the changes of mitochondrial oxidative respiratory function and cytochrome C oxidase (COX) activity. Methods: Adult male Wistar rats were randomly divided into 4 groups: control (C), medication (M), hypoxia (H), and medication plus hypoxia (MH). Rats in groups M and MH were administered by peritoneal injection of CAP (50 mg/kg) every 12 h for 7 d before decapitation, but those in groups H and MH were exposed to a hypobaric chamber simulating 5 000 m high altitude for 24 h. The rat cerebral cortex was removed and mitochondria were isolated by centrifugation. Mitochondrial respiratory function and COX activity were measured by Clark oxygen electrode. Results: Compared with Group C, Group H showed significantly elevated state 4 respiration (ST 4), decreased state 3 respiration (ST 3), and respiratory control rate (RCR) in mitochondrial respiration during acute hypoxic exposure. ST 3 in Group MH was significantly lower than that in Group C, but was not significantly different from that in Groups H and M, while ST 4 in Group MH was significantly lower than that in groups C and H. RCR in Group MH was higher than that in Group H, but lower than that in Group C. COX activity in Group H was significantly lower than that in Group C. In Group MH, COX activity increased and was higher than that in Group H, but was still lower than that in Group C. Conclusion: Acute hypoxic exposure could lead to mitochondrial respiratory dysfunction, suggesting that CAP preconditioning might be beneficial to the recovery of rat respiratory function. The change of COX activity is consistent with that of mitochondrial respiratory function during acute hypoxic exposure and CAP-administration, indicating that COX plays an important role in oxidative phosphorylation function of mitochondria from cerebral cortex of hypoxic rats.展开更多
基金国家自然科学基金面上项目(81573487):二氢神经酰胺类鞘脂及其代谢通路在慢加急性肝衰竭发生发展中的作用及防治措施研究中国医学科学院医学与健康科技创新工程重大协同创新项目(2017-12M-1-013):中药安全风险预警及防控国际合作项目(Grant ID4084):Applications and core technology university research(ACT-UR)proposal form
文摘目的利用Seahorse XF^e24海马细胞能量代谢分析系统分析对乙酰氨基酚(APAP)对人肝细胞线粒体有氧呼吸的整体影响,为APAP在能量代谢角度的毒性防控及毒性机制研究提供方法学的参考。方法体外培养人肝细胞系(HepG2),分别以1、2、4、8、16 mM APAP处理细胞24 h,MTT法检测细胞增殖情况,倒置显微镜观察细胞形态;BCA法定蛋白含量。采用Seahorse XF^e24海马细胞能量代谢分析系统建立HepG2细胞实验方法,并检测不同浓度APAP对人肝细胞线粒体有氧呼吸的影响和特点。结果 Seahorse XF^e24海马细胞能量代谢分析系统检测HepG2细胞能量代谢的最佳条件为:24孔板细胞密度2×10~4/孔,FCCP浓度为2μM。MTT结果中对人肝细胞增殖有显著抑制作用的APAP(4、8、16 mM)能干扰人肝细胞的线粒体有氧呼吸,其中4、8 mM APAP有降低肝细胞基础呼吸和ATP生成的趋势,16 mM APAP能显著抑制肝细胞的基础呼吸、最大呼吸和ATP合成。结论高剂量APAP(16 mM)在人肝细胞活细胞体系中能够显著抑制细胞能量代谢,对活细胞线粒体有氧呼吸显示显著毒性作用。
文摘Objective: To investigate the roles of chloramphenicol (CAP) preconditioning in the oxidative respiratory function of cerebral mitochondria in rats exposed to acute hypoxia during acute hypoxia by observing the changes of mitochondrial oxidative respiratory function and cytochrome C oxidase (COX) activity. Methods: Adult male Wistar rats were randomly divided into 4 groups: control (C), medication (M), hypoxia (H), and medication plus hypoxia (MH). Rats in groups M and MH were administered by peritoneal injection of CAP (50 mg/kg) every 12 h for 7 d before decapitation, but those in groups H and MH were exposed to a hypobaric chamber simulating 5 000 m high altitude for 24 h. The rat cerebral cortex was removed and mitochondria were isolated by centrifugation. Mitochondrial respiratory function and COX activity were measured by Clark oxygen electrode. Results: Compared with Group C, Group H showed significantly elevated state 4 respiration (ST 4), decreased state 3 respiration (ST 3), and respiratory control rate (RCR) in mitochondrial respiration during acute hypoxic exposure. ST 3 in Group MH was significantly lower than that in Group C, but was not significantly different from that in Groups H and M, while ST 4 in Group MH was significantly lower than that in groups C and H. RCR in Group MH was higher than that in Group H, but lower than that in Group C. COX activity in Group H was significantly lower than that in Group C. In Group MH, COX activity increased and was higher than that in Group H, but was still lower than that in Group C. Conclusion: Acute hypoxic exposure could lead to mitochondrial respiratory dysfunction, suggesting that CAP preconditioning might be beneficial to the recovery of rat respiratory function. The change of COX activity is consistent with that of mitochondrial respiratory function during acute hypoxic exposure and CAP-administration, indicating that COX plays an important role in oxidative phosphorylation function of mitochondria from cerebral cortex of hypoxic rats.
