Experimental Study On The Effects Of BFGF On Focal Cerebral Ischemia Reperfusion Injury In Rats

For the high incidence, mortality and disability rate, cerebrovascular disease(CVD) are seriously endangering man's health. The mechanism of neuronal injury and death have been being the emphasis of fundamental and clinical medicine study. Some researches indicate there are some inflammatory cells infiltrate into ischemic region after cerebral ischemia reperfusion. In the course of infiltration, ICAM-1 (intercellular adhesion molecule-l)plays a pitotal role. The expression of ICAM-1 increases in cerebrovascular endothelial cells after ischemia reperfusion. By using anti-ICAM-1 monolclonal antibody the cerebral ischemic injury is decreased. Neurons are found apoptosis after cerebral ischemia. Apoptotic cells are mainly located in cerebral penumbra and close related to the formation and expandation of infarction core. Researches indicate oxygen free radical contributes to neuronal apoptosis after cerebral ischemia reperfusien. Reducing the release of oxygen free radicals can restricts cell apoptosis.bFGF(basic fibroblast growth factor) is an important neuron nutrition factor and distributes extensively among ripe and unripe central nervous system. The expression of bFGF in ischemic region increases after cerebral ischemia reperfudion. External bFGF can promote neuron survival and antagonice excitatory amino acid toxicity in vitro. In resent years, researches show external bFGF can go through blood brainbarria(BBB), reduce infarction volume and suppress neuronal apoptosis after cerebral ischemia reperfusion. But the mechanism is unclear up to date. The purpose of this experiment is to observe the expression of ICAM-1 -. superoxide dismutase activity and the concentration of malondialdehyde in brain tissue ^ the change of neuronal apoptosis in ischemic cortex and investigate the mechanism of neuron death after focal cerebral ischemia reperfusion and the mechanism by which bFGF protect brain tissues.Materials and Methods1. Middle cerebral artery occlusion(MCAO) by sulture emboli was established with health male rats. Sham-operation contral rats received the operations without ischemia. Horner's sign in left side and paralysis of the right front limbs were observed to judge the success of MCAO model.2. 48 rats were randomly divided into three groups: namely sham-operation group(n=16). Ischemia-reperfusion group(n=16) and bFGF treatment group(n=16). At the time of MCAO, bFGF was injected intraperitoneally(10. g/kg) to rats in bFGF treatment group. The same dosage of normal saline was administrated intraperitoneally to rats in sham-operation group and ischemia-reperfusion group at the same time. Ischemia Ih and reperfusion 2h, the brains of 8 rats in every group were removed and processed for SOD, MDA detection. After ischemia Ih reperfusion 24h , another 8 rats in each group were anesthetized and perfused with 200ml normal saline and subsequently with 4% polyformaldehyed in O.lmmol/L Phosphylate buffer. Brains were removed.postfixed.embedded. sectioned and processed for HE staining. TUNEL detection and ICAM-1 immunohistochemistry staining.3. All the dates were expressed by (x ?s) and analysed statistically by one-way analysis of xariance among groups. Mest between two groups. The significant testing standard was . =0.05.Results1. Rats in ischemia-reperfusion group and bFGF treatment group showed Horner's sign in left side and paralysis of the right front limbs after focal cerebralischemia reperfusion, and rats in sham-operation group only showed Horner's signs in left side indicating the succession of MCAO model.2. The movements of the rats in bFGF treatment group were much better than ischemia-reperfusion group at 24h(P < 0.01) since reperfusion. Brain tissue section H.E stain show there was no infarction in sham-operation group, the shape and structure of the neurons were normal,there was no edema interstitial. There were obvious infarction in ischemia-reperfusion group, the neurons were found deformed and shrunken, nucleus and cytoplasm were concentrated, edema was obvious.