| Objective:To establish MCAO models of rats and investigate the protective effect of IPO on Rats brains which endure ischemia/reperfusion,especially to find out whether there are differences in protective effect of IPO on rats brains of different ages.Methods:There are totally 108 Healthy male SD rats including 36 infancy rats of 1-2 months(150-200g),36 young rats of 4-5 months(300-350g),36 middle-aged rats of 14-16 months(480-520g).The rats of each age group are separated into 3 groups randomly: Sham group,I/R group and IPO group.There are totally 9 treatment groups in this experiment,and there are 12 rats in each treatment group.We establish MCAO models of rats by the Methods of Longa.The I/R group means reperfusion of 24 hours after the ischemia period of 2 hours.In IPO groups,we repeat 15s/15s(reperfusion/ ischemia)there times after the ischemia period of 2 hours,then make the brain reperfusion for 24 hours.In the Sham group,the operations are similar to the I/R group besides there is no wire.Inserted.Each rat is given a score according to its neurological deficit symptoms,and evaluate the infarct size of 6 rats of each treatment group randomly and measure the cell apoptosis level of the other 6 rats of each treatment group.All the measurements are taken at 24 hours after reperfusion.Results:In Sham groups,rats get 0 score without neurological deficit symptoms and there is no infarct zone and there is very few apoptotic cells found by TUNEL.Compared with I/R group of each age,infancy IPO group rats get significant lower scores(P<0.05),but young IPO group rats and middle-aged IPO group rats are no significant different(P>0.05).Compared with I/R group of each age,IPO group rats of each age have significant smaller infarct size(P<0.05).Compared with I/R group of each age,IPO group rats of each age have significant fewer apoptotic cells found by TUNEL(P<0.05).Compared with infancy I/R group,the rats in young I/R group and middle-aged I/R group have significant higher scores(P<0.05),significant greater infarct size(P<0.05)and significant more apoptotic cells found by TUNEL(P<0.05).The rats in young I/R group and middle-aged I/R group have no significant difference in score,infarct size and the amount of apoptotic cells(P>0.05).Conclusions:IPO protect Rats brains which endure ischemia/reperfusion in each age group by reducing infarct size and the amount of apoptotic cells.The protective effect of IPO on rats brains of different ages are different,and protective effect in infancy group is stronger than others.Objective: To investigate the effect of ischemic postconditioning on the expression of JAK2-STAT3 and Bcl-2/Bax in rats endured ischemia/reperfusion,and explore the role of JAK2-STAT3 signaling pathway and the ratio of Bcl-2 to Bax played in the protective effect of ischemic postconditioning.Methods: 120 Healthy male SD rats of 4-5 months(280-320g)are separated randomly into Sham group(n=10),I/R group(n=50),IPO group(n=50),AG490 group(n=10).Then according to the time of reperfusion(6h,12 h,24h,48 h,72h),the rats in I/R group and IPO group are divided into 5 treatment groups.There are totally 12 treatment groups in this experiment,and there are 10 rats in each treatment group.Each rat is given a score according to its neurological deficit symptoms,and evaluate the infarct size of 4 rats of each treatment group randomly by TTC and measure the expression of JAK2-STAT3 and Bcl-2/Bax in hippocampus of the other 6 rats of each treatment group by Western Blot.Results: Compared with Sham groups,the rats in I/R group,IPO group and AG490 group have significant higher scores(P<0.05)and significant greater infarct size(P<0.05).Compared with Sham groups,the rats in I/R group have significant higher expression of p-JAK2 and p-STAT3 in hippocampus(P<0.05).Compared with I/R group,the rats in IPO group and AG490 group have significant lower expression of p-JAK2 and p-STAT3 in hippocampus(P<0.05).In I/R group and IPO group,the expression of p-JAK2 and p-STAT3 in hippocampus increase firstly,then decrease after the 24 h.Compared with Sham groups,the rats in I/R group have significant lower ratio of Bcl-2 to Bax(P<0.05).Compared with I/R group,the rats in IPO group and AG490 group have significant higher ratio of Bcl-2 to Bax(P<0.05).Conclusions: Ischemic postconditioning protect rats brain from ischemia/reperfusion injury by inhibiting cell apoptosis via down regulating JAK2/STAT3 signaling pathway.Ag490 protect rats brain through down regulating JAK2/STAT3 signaling pathway. |
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