| Objective: Intestinal ischemia-reperfusion may be a congenerous pathological and physiological phase during the intensive cure of commonly critical diseases such as intestinal obstruction and hypotension shock. Recently, there are more and more studies on the role of adhesion molecules in the intestinal ischemia-reperfusion. P-selecrin. as one member of the adhesion molecule families, mediate the interactions between activated platelets, inflammatory cells and endothelial cells, might play an important role in intestinal ischemia-reperfusionP-selectin is stored in granules called Weibel-Palade bodies of endothelial cell and a -granules of platelte. which is mobilized within minutes to the cell surface when cultured endothelial cells are exposed to histamine. thrombin. or oxidants . By mediating the rolling and recruitment of leukocytes on endothelial cells. P-selectin plays an important role in inflammation occurrence and development, It has been observed the changes of P-selectin expression in kidney, liver, and heart which were ischemia-reperfusion moulds. But its chanaes in tissues durins intestinalischemia-reperfusion have not experimental testimony in our country.Ischemic preconditioning refers to a phenomenon in which a tissue is rendered resistant to the deleterious effects of prolonged ischemia and reperfusion by exposure to brief periods of vascular occlusion. The protective effect of ischemic preconditioning was first described in the heart about a decade ago. Subsequent studies confirmed the efficacy of this phenomenon in reducing ischemic-reperfusion injury in a varietry of organs, including brain, liver, and skeletal muscle. But there are not much studies on intestinal ischemic-reperfusion. and people have different attitudes to it.The aims of the present study were to clarify1 the relationship between P-selectin and small intestinal ischemia-reperfusion. and to explore the effects of preconditioning and mAbs directed against P-selectin on intestinal ischemia-reperfusion and the mechanism of preconditioning.Methods: To investigated the effects of both preconditioning and mAbs directed against P-selectin on intestinal ischemia-reperfusion. male Sprague-Dawley rats (n=50) To induced intestinal ischemia, laparotomy was performed The superior mesenteric artery (SMA) was completely occluded with a microvascular clamp for 60 min, after which the clamp was removed, and the intestin was allowed to reperfuse for 60 min.To investigate the effects of both preconditioning and mAbs directed against P-selectin on intestinal ischemia-reperfusion. the following experimental groups were evaluated: all animals were randomized for group assignment as detailed below I R I group: animals subjected to 60 minutes of ischemia, followed by 60 minutes of reperfusion. MAb-anti-P-selectm group: animals sub]ected to adminstration of an mAb directed against P-selectin5 minutes previous to reperfusion : IPC group .'before the ischemia period (as in I R group), animals were subjected to 10 minutes of ischemia and 15 minutes of reperfusion: I RII group: animals subjected to adminstration of 1ml saline 5 minutes previous to reperfusion : Sham group: animals subjected to only anesthesia and laparotomy. At the end of protocol, venule blood and tissue samples of small intestine and remote organs (lung and liver) were taken. Blood samples uere processed to determine P-selectin blood level. The concentration of plasma P-selectm was determined with Enzyme Linked Immnosorbent Assay (ELISA). The P-selectin expression in tissue of small intestin. lung and liver are investigated through histological and immunhistochemical studies (LSAB). Results determination:in every leaf of section, the cytoplasm show distinct snuff color are positive. They are classified by positive cells proportion. Quantitative analysis: Firstly, positive expression (bufiy granule) are determined by lightmicroscope, and then the region of positive expression are quantified by utilizing Image-Pro PLUS comput...
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