The Effect Of BFGF On The Expression Of ERK And Apoptosis During Cerebral Ischemia And Reperfusion In Rats

Objective:Cerebrovascular disease, heart disease and malignant tumor are the three major etiopathogenisis of death. The complex change of pathophysiology, include interruption of cerebral blood flow, hypoperfusion, burn-out, ischemia-reperfusion damage, radical reaction, toxicity of excitatory amino acids, calcium overload and so on, after the genesis of cerebral ischemia could induce neuronal degeneration and necrosis, delayed neuronal death and/or apoptosis. bFGF can nourish cerebral nerves, glial cell and vascular endothelial cell directly, broaden cerebral vessels, increase cerebal blood flow, stabilize calcium channel, antagonise noxious substance toxicity, preserve neruon. MAPK cascade reaction was the key relationship between cytoplasm and cell nucleus, ERK was one of the most important members of MAPK iter, and its effect was transmitting signal from extracelluar to cell nucleus, regulating transcription factor for activating definite gene expression. Our experiments applicating MCAO reperfusion model observed the express variation rule after reperfusion 72h, the nerves function of rat, and cellular necrosis in light microscope, and investigated apoptosis cells through TUNEL method, also our study observed ERK positive cells expression in cerebral cortex and hippocamp CA1 region by Immunohistochemical method, discussing the mechanism of neuron death after focal cerebal ischemia reperfusion and bFGF protection as well as mechanism. Our study provided experiment and theory evidences for clinical application bFGF treatment of cerebrovascular disease.Method: To establish focal cerebal ischemia reperfusion rat model by line-lock method. Wister rats(n=36) were randomly divided into 3 groups: (1) sham operation group(n=12); (2) Ischemia and Reperfusion group (I/R group n=12); (3) bFGF-treated group (n=12). Operation group was ischemic for 2h and reperfusion for 36h. Then executed the rats 72h after reperfusion respectively, after perfusing fixation, reciped brain tissue routine par embedment, slice was treated by HE staining, TUNEL staining, and Immunohistochemical method, then analysis the image by image analytical system , detecting ERK expression as well as the variation of apoptosis neuron in rat hippocampus CA1 region.Results:(1)HE staining in light microscope: the apoptosis cells of I/R group were obviouely increased compare with sham operation group(P<0.05), the apoptosis cells of bFGF-treated group were decreased compare with I/R group(P<0.05). (2)TUNEL staining in light microscope: we found the TUNEL positive cells occasionally in sham operation group, a great number of TUNEL positive cells in I/R group and bFGF-treated group, but the TUNEL positive cells of bFGF-treated group was less than I/R group, the comparison of the two group has statistical significance(P<0.05). (3)ERK Immunohistochemical method staining in light microscope: we found ERK expression occasionally in hippocampus CA1 region in sham operation group, the number of ERK express in the same region was increased in I/R group compare with sham operation group, meanwhile the number of bFGF-treated group was more than I/R group, the comparison of the two group has statistical significance(P<0.05).Conclusion: 1. Cerebal ischemia reperfusion damage maybe causing neuron apoptosis in rat hippocampus CA1 region and cerebral cortex,bFGF might diminished neuron apoptosis for protection of rat cerebal ischemia reperfusion damage.2. The number of ERK express in the same region was increased in I/R group compare with sham operation group, The protection of bFGF for rat cerebal ischemia reperfusion damage may be concerned with ERK expression.