Effects of different time administration of propofol on cytochrome c in cytoplasm in rat hippocampal neurons with hypoxia-reoxygenation injury

Abstract

Objective To investigate the effects of different time administration of propofol on cytochrome c (Cyt c) in the cytoplasm in rat hippocampal neurons with hypoxia-reoxygenation (H/R) injury.Methods Primary cultured hippocampal neurons were randomly divided into 5 groups ( n =5 each):control group (group C),model of H/R injury group (group M),and different time administration of propofol groups (group Ⅰ,Ⅱ,Ⅲ ).In groups M,Ⅰ,Ⅱ and Ⅲ,the neurons were exposed to 95％ N2 + 5％ CO2 for6 h followed by 12 h reoxygenation.In groups Ⅰ, Ⅱ,Ⅲ,propofol was added to the culture medium before hypoxia,immediately after reoxygenation and at 2 h of reoxygenation (T0-2) respectively,with the final concentration of 20 μmol/L.The cell apoptosis was observed at T1,2 and at 24 h of reoxygenation ( T3 ) and the concentration of Cyt c in the cytoplasm was detected at T1-3.Results Compared with group C,the concentration of Cyt c in the cytoplasm was significantly increased at T1-3 in group M and at T1,2 in groups Ⅰ,Ⅱ,Ⅲ (P ＜ 0.05).Compared with group M,the concentration of Cyt c in the cytoplasm was significantly decreased at T1-3 in group I and at T1,2 in groups Ⅱ and Ⅲ ( P ＜0.05).The concentration of Cyt c in the cytoplasm was significantly higher at T1,2 in groups Ⅱ and Ⅲ than in group Ⅰ,and at T2 in group Ⅲ than in group Ⅱ ( P ＜ 0.05).The neuronal apoptosis was significantly decreased in groups Ⅰ,Ⅱ and Ⅲ as compared with group M.Conclusion Different time administration of propofol can reduce the mitochondrial Cyt c release to the cytoplasm,inhibit apoptosis in hippocampal neurons,and reduce H/R injury in rats,with better effect when given before hypoxia. Key words: Propofol; Hippocampus; Cell hypoxia; Cytochromes c