Ischemic postconditioning ameliorates pia mater microcirculation in rats subjected to cerebral ischemia reperfusion
YAO Shu-tong1,2,LIU Xiu-hua1,TANG Xu-ming1,SUN Sheng1,WANG Jia-fu2(1Department of Pathophysiology,Chinese PLA General Hospital,Beijing 100853,China; 2Department of Pathophysiology,Taishan Medical College,Taian 271000,China.
AIM:To investigate the ameliorative effect of ischemic postconditioning (I-postC) on pia mater microcirculation in rats subjected to cerebral ischemia reperfusion (I/R) and its mechanisms. METHODS:Thirty-two male Wistar rats were randomly divided into sham,I/R,I-postC,and ischemic preconditioning (IPC) groups. The global cerebral I/R injury was induced by shunting carotid artery in rats. Pia mater microcirculation and cerebral microcirculatory perfusion were measured after reperfusion. The content of soluble intercellular adhesion molecule-1 (sICAM-1) in plasma was detected using enzyme linked-immunosorbent assay (ELISA). Myeloperoxidase (MPO),malondialdehyde (MDA),and superoxide dismutase (SOD) in cerebral tissue were detected. The expressions of vascular endothelial cell cadherin (VE-cadherin) and NF-κB p65 in cerebral tissue were assayed by Western blotting. RESULTS:(1) The disturbance of the blood flow in microvessel induced by I/R was improved significantly by I-postC. In addition,I-postC alleviated significantly the decrease in diameters of microvesseles,cerebral microcirculatory perfusion and cerebral VE-cadherin content induced by I/R (P0.05). (2) sICAM-1 in plasma,MPO and MDA in cerebral tissue decreased,but SOD activity in cerebral tissue increased in I-postC group,compared with those in I/R group (P0.05 or P0.01). The over-expression of NF-κB p65 induced by I/R was relieved by I-postC (P0.05). CONCLUSION:I-postC ameliorates pia mater microcirculation in rats subjected to cerebral I/R through suppressing the activation of polymorphonuclear neutrophils mediated by ICAM-1.