ABSTRACT
Objective To observe the effect of hyperbaric oxygenation (HBO) on apoptosis-inducing factor (AIF) and Caspase-3 levels in rats with permanent middle cerebral artery occlusion (MCAO),and to elucidate the apoptosis pathways.Methods Sixty Sprague-Dawley rats were subjected to permanent MCAO and then randomly divided into a control group and an HBO group,each of 30.Three hours later the rats of the HBO group were put into a hyperbaric cabin held at a pressure of 0.2 MPa for 9 hours.They inhaled supplementary oxygen at the 1st,3rd,5th,7th and 9th hour while the rats in the control group inhaled air at normal pressure.The neurological outcome was measured at the 3rd,13th and 72nd hour after the MCAO using Garcia scores.Apoptosis in the tissue of the ischemic penumbra,nuclear and mitochondrial AIF and Caspase-3 levels were measured at the 13th and 72nd hours after the modeling.Results The scores were significantly higher at the 13th hour than after the 3rd hour in both groups,and then even higher at the 72nd hour.Apoptosis was evident in the ischemic penumbra at the 13th and 72nd hours in both groups,but the number of cells was less at the 72nd hour than at the 13th hour in the control group.There was significantly less apoptosis in the HBO group than in the control group at the 13th hour.The average AIF level had significantly decreased in the nuclei and increased in the mitochondria by the 72nd hour compared with the 13th hour in both groups.The average levels of nuclear AIF at the 13th hour and the 72nd hour were lower than those in the mitochondria.But they were significantly higher in the HBO group than in the control group at the same time points.The levels of Caspase-3,normally zero,had increased by the 13th hour in both groups.The average level of Caspase-3 was significantly lower in both groups at the 72nd hour than at the 13th hour.Conclusions HBO can improve neurological function,inhibit the transfer of AIF from the mitochondria to the nucleus and reduce Caspase-3 levels.The mechanism may involve reducing apoptosis through caspase-dependent and caspase-independent pathways in the mitochondria.
ABSTRACT
@#Objective To observe the effect of single intensive hyperbaric oxygenation (HBO) on cytochrome C and caspase-3 in rats af-ter permanent middle cerebral artery occlusion (MCAO) very early. Methods Forty-eight male Sprague-Dawley rats were subjected to per-manent MCAO model using the intraluminal suture method, and were divided into control group (n=24) and HBO group (n=24). The HBO group stayed in the hyperbaric cabin with a pressure of 0.2 MPa for 9 hours 3 hours after MCAO. They were measured with Garcia scores 3 hours, 13 hours and 24 hours after MCAO. Apoptosis cells of ischemic penumbra tissue were investigated with TUNEL 13 hours and 24 hours after MCAO, while the level of cytochrome C and caspase-3 were measured with ELISA. Results The Garcia scores increased 13 hours and 24 hours after MCAO in both groups, but there was no significant difference between groups (t<2.07, P>0.05). The apoptosis cells were found in both groups 13 hours and 24 hours after MCAO, and less in the HBO group than in the control group (t>6.57, P<0.01). The levels of cytochrome C and caspase-3 were less in the HBO group than in the control group 24 hours after MCAO (t>2.41, P<0.05). Conclusion A single intensive HBO in very early stage may improve neurological function after cerebral ischemia in rats, which may associ-ate with the inhibition of cytochrome C and caspase-3 to reduce cell apoptosis.