AAS ›› 2015, Vol. ›› Issue (3): 310-316.doi: 10.16098/j.issn.0529-1356.2015.03.004

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Limb remote ischemic postcondtioning promoting the expression of  heat shock protein 70 in the rat cortex after focal cerebral ischemia reperfusion injury

ZHOU Fang-fang1 LI Shuai2 QI Wen-qian1 ZONG Yong-hua1 ZHANG Ming-xiao1 YANG Hui-jun2 HU Xiao-song 2*   

  1. 1.Graduate Department; 2.Morphology Laboratory,Chengdu Medical College, Chengdu 610500,China
  • Received:2014-11-03 Revised:2015-01-17 Online:2015-06-06 Published:2015-06-06
  • Contact: HU Xiao-song E-mail:woodwind@cmc.edu.cn

Abstract:

Objective To explore the underlying molecular mechanisms of limb remote ischemic postconditioning (LRIP) protective role in the brain by observing the localization and changes of positive cells expression of heat shock protein 70 (HSP70) in focal cerebral ischemia-reperfusion injury (I/R) of rat cortical infarct areas after remote ischemic postcondtioning treatment. Methods A SD rat model of focal cerebral ischemia reperfusion was induced by intraluminal 1 hour transient middle cerebral artery occlusion with a nylon monofilament suture.Ischemic animals were randomly assigned to 3 groups: sham group, I/R group and LRIP group, 5 animals each group.The LRIP performed immediately after reperfusion(LRIP was generated by 3 cycles of 10 minutes occlusion/10 minutes release of the bilateral hind femoral artery used rubber band). To determine whether the model of MCAO was successful, Zea longa score method was used. Rats were sacrificed on 1day or 3days after reperfusion and the brain was obtained by decapitation. Rats were evaluated for neurological deficits just before sacrifice by Garcia. Brains were harvested for infarct size estimation used 2, 3,5-triphenyl tetrazolium chloride(TTC). Western blotting was used to analyze the quantitative alterations of HSP70.Immunohistochemistry and double immunofluorescence histochemistry were used to observe the distribution, type and number of positive cells of HSP70. Results Compared with I/R group, LRIP treatment significantly improved neurological functions(P<0.05)and decreased infract size(P<0.05)as well as upregulated HSP70 expression. There was no statistically significant difference between LRIP and I/R group at 1day (P>0.05)except for that of 3days(P<0.01). HSP70 was localized predominantly in neurons and endothelia cells and astrocytes in ischemic peripheral areas. Conclusion LRIP treatment could improve neurological functions as well as decrease infract size. According to the results, we speculate this protective effect likely by increasing the neurons, endothelia cells and astrocytes expression of HSP70 in ischemic peripheral areas.