The Caspase-9 MRNA And RTP801 MRNA Expression Affects Of EPO On Globe Ischemia Rat Model

Objective Explore the expression of Caspase-9 mRNA and RTP801 mRNA in hippocampus with globe ischemic rat model; The effects of EPO treatment on expression of Caspase-9 mRNA and RTP801 mRNA and on the condition of apoptosis in hippocampus of this rat model; The protective mechanism of EPO for ischemic hippocampus was explored in this study.Methods The globe ischemic rat model was used in our study. 66 SD rats were divided randomly into three large groups: experiment group, EPO treatment group with 30 rats in each group, and 6 rats in control group. The rats in latter group were treated with EPO injection into abdominal cavity (4000U/ kg body weight/day) and one time with the same dosage in each day before sacrificed. Each large group was divided into 5 groups with 6 rats in each group according to reperfusion time 6 hours, 12 hours, 24 hours, 48 hours and 72 hours after ischemia. Brains of rats in 2 large groups were removed after perfusion for TUNEL staining and RT-PCR. The rats in control group were treated with 1ml saline injection into abdominal cavity and sacrificed 3 days later. TUNEL sections were observed with microscope and image processing system and TUNEL positive cells were also counted. The gel images of DNA after RT-PCR were captured with gel image processing system and analyzed. Volume of Caspase-9 mRNA and RTP801 mRNA was figured out and analyzed withspss11.5 statistics software package.Results The expression of Caspase-9mRNA (1) After ischemia, the expression of Caspase-9mRMA were significantly changed accord the time. It increased obviously at 6h(0.82±0.026), reached it's maximum at 12h(1.12 ± 0.016), and remain high level at 24h(0.86 ± 0.023). (2) The effect of EPO treatment on expression of Caspase-9mRNA in cortex of this rat model was obviously; the difference between experiment group and EPO treatment group at each time point was obvious (all p<0.05) .The expression of RTP801 mRNA: Compared with the control group, there were more RTP801 mRNA expression statistically except 72 hours time point in both large groups. There was more significantly RTP801 expression in experiment group than that of EPO treatment group at each time point except 72 hours.TUNEL Staining: With reperfusion time extending, number of TUNEL positive nerve cells grew larger gradually in both experiment group and EPO treatment group. There were more TUNEL positive cells in ischemia groups than EPO treatment groups at the 12 hours, 24 hours, 48hours and 72 hours after reperfusion. TUNEL positive cells increased significantly from 24 hours of reperfusion in ischemia group, however, TUNEL positive cells increased significantly from 48 hours in EPO treatment group.Conclussion (1) EPO could protect the neurons after the ischemia-reperfusion injury, and maybe one of it's workings is it could decrease the expression of Caspase-9. (2) Expression of RTP801 mRNA increases sharply and significantly in rat of globe ischemia model and EPO can inhibit the expression of RTP801 mRNA in globe cerebral ischemia rat model but the mechanism is still unknown. (3) EPO can significantly reduce apoptosis induced by cerebral globe ischemia.Significance To study the brain protective effects of EPO on ischemia-reperfusion injury .It would offer new thinking pathway for clinical drug treatment of ischemic cerebral vascular disease.