视神经切断诱导金黄地鼠脑内视觉通路小热休克蛋白27的表达

目的 观察成年金黄地鼠左侧视神经眶内切断术后，视交叉、视束、外侧膝状体以及上丘内小热休克蛋白27(small heat shock protein，HSP27)表达的变化。方法 免疫组织化学染色法及光密度测定。结果 在正常对照和手术对照组，双侧视交叉、视束、外侧膝状体和上丘未见明显免疫反应物，光密度值之间亦无显著差异。而在实验组，与左侧相比，右侧视交叉、视束、外侧膝状体和上丘免疫组织化学染色明显增强。术后1周，右侧脑内视觉通路可见免疫反应物明显沉着的阳性细胞，形态类似星形胶质细胞。统计学分析显示，视交叉、外侧膝状体和上丘左、右两侧的光密度差值在术后1周时最大，至术后第2周迅速降低，以后下降趋势减缓，到术后8周仍可见右侧光密度值高于左侧。结论 一侧视神经切断后，对侧视交叉、视束、外侧膝状体和上丘等区域均有HSP27表达的增强，并可持续至术后8周之久。提示上述区域HSP27表达增强与视觉通路的损伤有关，但其发生机理及生物学意义尚待进一步研究。

TRANSECTION OF THE OPTIC NERVE INDUCES EXPRESSION OF THE SMALL HEAT SHOCK PROTEIN HSP27 IN THE OPTIC PATHWAY OF GOLDEN HAMSTER

Objective To observe the expression of the small heat shock protein (HSP27) in the optic chiasma (OC), optic tract (OT), dorsal lateral geniculate body(LG) and superior colliculus (SC) of the adult golden hamster after intraorbital transection of the left optic nerve (ON). Methods The experimental animals were left to survive for l, 2, 3, 4, 5, 6, 8 weeks following ON transection. The animals were perfused with formol-saline and brains were excised, sectioned and stained with the immunohistochemistry. The sections were observed under the light microscope, the optical density (A) was measured and the data were analysed statistically. Results Immunohistochemical results indicated that the HSP27-expressions were not different between the right and left side of the OC, OT, LG and SC in normal or sham-operation controls. However, following transection of the left ON, HSP27 immunohistochemical stainings in the right site of OC, OT,LG and SC were increased, comparing with the left side. The maximum difference of HSP27 immunostaining between the right and left side appeared in the lst week following left ON axotomy. The sharply decrease of the A difference occurred at the 2nd week after axotomy with insignificant changes in the subsequent several weeks. And the significant A difference was observed in most time except 6th week. Most of HSP27-positive cells had morphological appearances similar to astrocytes with smaller cell body and numerous processes. Conclusion After the transection of monolateral ON, HSP27 expressions in the contralateral optic pathway of brain increased and persisted up to 8 weeks. This result suggested that the increase of HSP27 expression had something to do with the injury of the optic pathway, but the mechanism and biological significance of the increase in HSP27 expression level required to be studied further.;