Effect of CAP-administration on respiratory function and cytochrome c oxidase avtivity in mitochondria from brain cortex of rats exposed to hypoxia / 第三军医大学学报

ABSTRACT

Objective To understand the changing aspects of CAP-administration on mitochondrial oxidative phosphorylation function and cytochrome c oxidase (COX) activity during hypoxia exposure and their mechanisms. Methods Except the control group (C group), adult male Wistar rats were exposed to a hypobaric chamber simulated 5 000-meter high altitude for 23 h every day for 0, 1, 5, 15, 30 d (H_ 0, 1, 5, 15, 30 ) respectively and administrated CAP (100 mg/kg, intraperitoneal injection) every 12 h for 7 d before sacrificed by decapitation. Mitochondrial respiratory function and COX activity were measured by Clark oxygen electrode and polarography, respectively. Results As compared with C group, mitochondrial state 3 respiration (ST_3) and respiratory control rate (RCR) and oxidative phosphorylation rate (ORP) and COX activity in H_0+CAP group all decreased significantly, but by prolonging hypoxia exposure increased and restored to the control level. Conclusion Mitochondrial respiratory function, oxidative phosphorylation efficiency and COX activity in rat brain could improve by administrating CAP during hypoxia exposure and almost reach to the control level by prolonging hypoxia exposure.