The Studies Of The Role Of Tissue Plasminogen Activator In Brain Injury After Cerebral Ischemia

PART ONE THE EFFECT OF ENDOGENOUS TISSUE PLASMINOGEN ACTIVATOR ON CEREBRAL ISCHEMIC REPERFUSION INJURY IN RATSObjective: To explore the effect of endogenous tissue plasminogen activator ( tPA) expression on brain injury after MCAO reperfusion and further to evaluate whether tPA Stop exerts neuroprotection Methods: Healthy Sprague-Dawley rats were divided into three groups: Sham, Control and Experiment group. Each group was divided into three subgroups: 6 h,12 h,24 h after MCAO reperfusion. MCAO model were copied immediately after intraventricle injection. At each time point, rats were scored as standard neurobehavioral tests and then sacrificed. Infact volume was measured by TTC staining. The neuron survival rate and the number of apoptosis cell were assessed. The expression of tPA and tPA mRNA were evaluated by immunohistochemistry and in situ hybridization.Results: 1) There are large number of endogenous tPA expression after MCAO reperfusion . In early stage of MCAO reperfusion, it was mainly expressed by vascular endothelial cell. At 24 h after MCAO reperfusion, glias also expressed a great deal of tPA. 2) Endogenous tPA expression may aggravate ischemic neuronal damage after focal cerebral ischemia. It may increase infarct volume and TUNEL positive cells,...