Effects of propofol preconditioning on anoxia-reoxygenation induced apoptosis in rat hippocampal neurons

Aim To determine what effects propofol exerts on apoptosis in hippocampal neurons caused by anoxia-reoxygenation.Methods Newborn SD rats(24 h after birth) weighting 5 to 6 grams were decapitated,and hippocampal tissue was isolated and hippocampal neurons were prepared by digestion with tryp-sin.After being cultured for 9 to 10 d,the hippocampal neurons were randomly assigned to one of 5 groups:Control group(group A);CoCl2 group(group B),treated with 300 μmol·L-1(the other groups were same)CoCl2 for 4 h,cultured with normal medium for 24 h,then stimulated with no serum media;intralipid group(group C),pretreated the neurons with 10% intralipid 90 μl for 1 h and then treated as group B;propofol group(group D),pretreated the neurons with 100 μmol·L-1 propofol for 1 hour,then treated as group B;7-NI group(group E),treated as group D,but CoCl2 and 3.3 μl 7-NI(25 g·L-1) were added at the same time.MTT method and FACS were used to detect the proliferation and apoptosis of neurons.RT-PCR method was used to show the expression of neuronal nitric oxide synthesis and apoptosis related gene in propofol preconditioning.Results The results were compared between intralipid group and CoCl2 group,and the difference was not significant(P0.05).When pretreated with propofol,neurons proliferation increased and apoptosis decreased(P0.05 or P0.01).Neuronal nitric oxide synthesis was up-regulated after preconditioning;meanwhile,Bcl-2 gene was up-regulated and cyclinD1 gene was down-regulated.But these regulation can be suppressed by inhibitor of neuronal nitric oxide synthesis(P0.05 or P0.01).Conclusion Preconditioning with 100 μmol·L-1 propofol can protect hippocampal neurons against anoxia-reoxygenation injury,neuronal nitric oxide synthesis and apoptosis related gene play an important part in these protective effect.