伽玛刀照射正常大鼠海马组织的放射生物学研究

目的研究伽玛刀照射对正常大鼠海马组织的放射生物学作用,探讨伽玛刀作用于正常脑组织的机制,为立体定向放射外科的开展提供理论依据。方法利用自行设计的伽玛刀动物定向头架,应用不同剂量的伽玛射线对大鼠海马组织进行照射,原位杂交观察c-fosmRNA和HSP70mRNA表达,免疫组化观察FOS、HSP70、GFAP和bcl-2蛋白表达。结果c-fosmRNA在照射后3h、7d出现2个高峰,HSP70mRNA在照射后1~3h即有表达。FOS、HSP70、GFAP和bcl-2蛋白表达随照射时间和部位的不同而各有自己的特点。结论自行设计的伽玛刀动物定向头架定位准确、可靠。c-fos和HSP70表达说明伽玛刀照射虽局限于海马,但引起的反应却是强烈的。bcl-2具有抑制电离辐射所致细胞凋亡作用,GFAP阳性细胞反应可作为脑组织损伤的一种标志。

Radiobiological response to rats hippocampal tissue irradiated with gamma knife

Objective To investigate the radiobiological response and its mechanism of rat hippocampus irradiated with gamma knife and to provide theoretic basis for further development of stereotactic radioneurosurgery.Methods Hippocampus of rats was irradiated by different doses of gamma knife with stereotactic lathe-hedd for rat. Expression of c-fos mRNA,HSP70 mRNA,FOS,HSP70,GFAP and bcl-2 were detected with in situ hybridization and immunhistochemistry.Results Two pinnacle of c-fos mRNA appeared after irradiation at 3h and 7d respectively.Expression of HSP70 mRNA can be detected at 1~3h after irradiation.The expression of FOS,HSP70,GFAP and bcl-2 showed particular character consistent with position and time.Conclusion The expression of c-fos and HSP70 indicated that intensive response for gamma knife although limited irradiation.Expression of bcl-2 could inhibit the apoptosis response to irradiation and GFAP positive cell response could be used as one of the criteria of the severity of brain injury.