Objective To investigate the influence of ozagrel sodium (OS) on cerebral ischemic tolerance in rat induced by focal ischemic preconditioning (IPC) and on expression of nuclear factor ?B (NF ?B) in rats Methods Fourty five rats were divided into 3 groups The animals were subjected to 2 h middle cerebral artery occlusion (MCAO) 3 days after 10 min IPC, IPC+OS and sham surgery (SS) respectively. After 22 h reperfusion, the rats were killed and the infarct volume, brain water content and NF ?B immunoreactivity were compared among 3 groups. Results Compared with IPC+ MCAO group, there were a furtber decrements in farct volume (93 75?13 40 vs 130 92?14 59, P

Objective To observe the effects of Tongxinluo on cerebral ischemic tolerance and expression of Bcl-2 and Bax in rats with cerebral infarction.Methods The neurophysical assessment and the volume of the cerebral infarction in Tongxinluo group,middle cerebral artery occlusion(MCAO)group,preconditioning and MCAO(PC-MCAO)group were determined at different time point.The expression of Bcl-2 and Bax were measured with immunohistochemitry and the apoptosis of the nerve cells were detected with TUNEL.Results Among these groups in the corresponding time,the neurophysical marks of Tongxinluo group was the lowest and the cerebral infarction volume was the smallest at 24 h,3 d and 5 d points.The Bcl-2 positive neurons were the highest,while the Bax positive neurons and the apoptosis rate of nerve cells were the lowest around the necrotic areas in Tongxinluo group(P<0.05).Conclusion Tongxinluo can improve the cerebral ischemic tolerance and increase the expression of Bcl-2 and decrease that of Bax around the necrotic area after cerebral ischemia in rats.

Objective To explore the effect of δ-opioid receptor (DOR)on ischemic tolerance of rat brain.Methods The focal ischemic tolerance models of Sprague Dawley rats were established using the twice suture method with the middle cerebral artery occlusion (MCAO).A total of 24 male Sprague Dawley rats were randomly divided into sham group,ischemia (MCAO) group,sham +ischemia (sham+ MCAO) group and ischemic preconditioning + ischemia (IP+ MCAO) group (n=6,each).The neurological status was assessed using Zea-Longa neurological deficit scores at 7 days after cerebral infarction.The mRNA expressions of DOR,Bax,Bcl-2 in hippocampus in ischemic rat brain were detected by RT-PCR method.Results The Zea-Longa neurological deficit scores were 0.0±0.0,2.6±0.5,2.8±0.6 and 1.5±0.6 in Sham group,MCAO group,Sham+MCAO group and IP+ MCAO group,respectively at 7 days after cerebral infarction.The scores had significant differences among MCAO group,Sham+ MCAO group and IP+ MCAO group (both P＜0.01),but no difference between MCAO group and Sham+MCAO group(P＞0.05).The mRNA expressions of DOR and Bcl-2 were higher and Bax mRNA expression was lower in IP+MCAO group than in MCAO and Sham+ MCAO groups (all P＜0.01).Conclusions Ischemic preconditioning may increase the mRNA expressions of DOR and Bcl-2,reduce Bax mRNA expression,and improve the neurological status in rats.

BACKGROUND:Cerebral ischemia tolerance can promote proliferation of autologous neural stem cells in the hippocampus of cerebral infarction rats, but panaxtrial saponins effects on the proliferation of autologous neural stem cells in the brain have not been reported. OBJECTIVE:To explore the relationship of panaxtrial saponins, ischemic preconditioning and proliferation of endogenous neural stem cells in the hippocampus of rats at 7 days after cerebral infarction, and to observe the effect on neurobehavioral scores of rats after cerebral infarction. METHODS:Fifty Sprague-Dawley rats were included and randomly divided into five groups:sham group, ischemia group, ischemic control group, ischemic preconditioning group, and panaxtrial saponins group. In the latter four groups, acute models of cerebral infarction were established using Zea-Longa method. In the sham group, only an incision was made on the neck. The focal-focal ischemic tolerance models were established with twice suture method in the ischemic preconditioning and panaxtrial saponins groups. Sham operation was instead of ischemic preconditioning in the ischemic control group. In the panaxtrial saponins group, rats were given intraperitoneal injection of 100 mg/kg panaxtrial saponins at 7 days before modeling. RESULTS AND CONCLUSION:After 7 days of cerebral infarction, the neurobehavioral score and the number of neural stem cells in the hippocampus were significantly increased in the ischemia group (P<0.01);compared with the ischemia group, the neurobehavioral scores were lowered in the ischemic preconditioning and panaxtrial saponins groups (P<0.01), while the number of neural stem cells in the hippocampus was increased (P<0.01). However, there was no difference between the ischemic preconditioning and panaxtrial saponins groups (P>0.05). In addition, differences in the neurobehavioral scores and the number of neural stem cells in the hippocampus were insignificant between the ischemic control group and ischemia group (P>0.05). These findings indicate that panaxtrial saponins can play a role similar to ischemic tolerance, and thus improve neurologic impairment in rats with cerebral infarction.

Objective To investigate the effect of brain ischemic preconditioning (IP) combined with traditional Chinese medicine three seven three alcohol saponin (PTS) on proliferation of endogenous neural stem cells and the mRNA expressions of delta opioid receptor (DOR),Bax,Bcl-2 in hippocampus at 7d post middle cerebral artery occlusion (MCAO).Methods The focal-focal ischemic tolerance models were established with twice suture method.80 SD rats were included and randomly divided into 5 groups:sham group,MCAO group,sham+ MCAO group,IP+ MCAO group,PTS+MCAO group (n=16 each).We chose 10 SD rats from each group to evaluate their neurological status,and made BrdU fluorescent immunolabeling.In addition,we chose the other 6 SD rats to detect the expression levels of DOR,Bax and Bcl-2 mRNA in ischemic region in hippocampusby using RT-PCR.Animals were given one set of BrdU injections (on day 6,three times,4h apart,50mg/kg) to label the proliferating cells.The neurological status was assessed by using Zea Longa neurological deficit scores at 7 days following cerebral infarction.Results Zea longa neurologic deficit scores in MCAO group and sham+ MCAO) group had significantly differences with IP+ MCAO group and PTS+ MCAO group respectively at 7d post MCAO(P＜0.01).There was no significant differeuce in Zea-longa neurologic deficit scores between MCAO group versus sham+ MCAO group,and IP+ MCAO group versus PTS+ MCAO group(P＞0.05).The number of BrdU+ ceils in hippocampus had significant differences between IP+ MCAO and PTS+ MCAO groups at 7d post MCAOand three groups of sham,MCAO and sham+ MCAO respectively (P＜0.01).There was no difference in the number of BrdU+ cells between MCAO versus Sham + MCAO groups and IP + MCAO versus PTS+MCAO groups(P＞0.05).DOR and Bcl-2 mRNA expression levels were higher and Bax mRNA expression level was lower in IP+ MCAO group than in MCAO,Sham+ MCAO and PTS+MCAO groups (P＜0.01).There were no significant differences in DOR,Bcl-2 and Bax mRNA expressions among MCAO,Sham + MCAO and PTS + MCAO groups (P＞ 0.05).Conclusions Acute cerebral infarction can induce the proliferation of endogenous neural stem cells in hippocampus in SD rats.IPC can facilitate the proliferation of endogenous neural stem cells in hippocampus afteracute cerebral infarction,improve the symptoms of neurologic dysfunction,increase DOR and Bcl 2 mRNA expressions,and reduce Bax mRNA expression in SD rats.PTS can facilitate the proliferation of endogenous neural stem cells in hippocampus after acute cerebral infarction in SD rats,and improve the symptoms of neurologic dysfunction,but it has no influence on the expressions of DOR,Bcl-2 and Bax mRNA.

Objective To investigate the influence of focal ischemic preconditioning on the expression of heat shock protein 70(HSP70) and ischemic tolerance Methods 42 SD rats were divided into 3 groups in which control group received sham operation only, and the other two groups received 2 hours of middle cerebral artery occlusion(MCAO) followed by 22 hours of reperfusion with or without 10 minutes of ischemic preconditioning 3 days before Infarct volume and HSP70 immunoreactivity were evaluated in each group Results Compared with the sham operated group, there was a smaller infarct volume( P

Objective To investigate the effect of focal cerebral ischemic preconditioning (IPC) on brain edema and the expression of nuclear factor-?B( NF-?B) and its target gene MMP-9. Methods Forty-five SD rats were divided into 3 groups in which control group received sham surgery only, and the other two groups received 2 hours of middle cerebral artery occlusion (MCAO) followed by 22 hours of reperfusion with or without 10 minutes of IPC 3 days before. Brain water content, expression of NF-?B and MMP-9 mRNA were evaluated in each group by wet-dry weight method, immunohistochemistry staining and RT-PCR. Results Compared with the SS group, there was a lower NF-?B immunoreactivity and MMP-9 mRNA level (16 098.2?1 265.3 vs 23 565.8?1 978.4,50.7% vs 84.1%, P

Objective To observe the effect of focal cerebral ischemic preconditioning on the expression of glial fibrillary acidic protein (GFAP) and to investigate the significance of astrocyte activation in cerebral ischemic tolerance.Methods Thirty-six healthy male SpragueDawley rats were randomly divided into reischenmic,ischemic and control groups (n = 12 in each group) after ischemic preconditioning.The former two groups received 10 minutes middle cerebral artery occlusion (MCAO) preconditioning or sham operation 3 days before the 2-hour MCAO.The rats were killed 24 hours after the second MCAO.The control group only receivedthe two sham operations with an interval of three days.The infarct volume,histopathological changes,and GFAP expression in each group were compared.Results The infarct volume after ischemic preconditioning in the reischenmic and ischemic groups was 136.85 ± 14.51 mm3and 281.37 ± 29.93 mm3 respectively.The former was significantly reduced 53.15%compared to the latter (P =0.007).At the same time,neuronal degeneration and necrosis was reduced significantly,and GFAP expression was upregulated significantly (the mean absorbance for immunohistochemical staining in both groups was 102.66 ± 8.39 and 86.28 ± 6.19respectively,P = 0.009) after ischemic preconditioning in the reischemic group.Conclusions Focal ischemic preconditioning may induce brain ischemic tolerance and promote GFAP expression.The activation of astrocytes may be one of the mechanisms of cerebral ischemic tolerance.