大鼠脑出血后三价铁沉积及其相关铁转运体的实验研究

Role of ferric iron transporters on iron accumulation in brain after rat intracerebral hemorrhage

目的本实验通过观察实验性大鼠脑出血后不同时间段三价铁的沉积颗粒与转铁蛋白(Tf)、转铁蛋白受体(TfR)及铜蓝蛋白(CP)之间的动态变化及相关性,旨在探索三价铁及其内源性的铁转运体在脑出血后继发性脑损害中的影响及作用机制。方法采用大鼠Ⅳ型胶原酶定位注射制造脑出血模型,应用摩罗利(Mallory)铁染色法观察不同组别及时间段的三价铁沉积,免疫组化法分别观察不同时间段Tf、TfR及CP的表达变化。结果脑出血3、7、14d组较同期假手术组三价铁沉积显著增多,且以第14天最多;脑出血各组Tf免疫阳性细胞数显著增多,且以第3～7天组最多;脑出血第1、3、7天组TfR及CP免疫阳性细胞数显著增多,以第3～7天表达最多;相关分析显示三价铁沉积颗粒与Tf、TfR免疫阳性细胞呈显著正相关,CP免疫阳性细胞与Tf、TfR免疫阳性细胞呈显著正相关。结论脑出血后三价铁沉积可诱导Tf及TfR的表达,Tf/TfR表达上调可能参与脑组织内铁的转运及清除;脑组织内三价铁的沉积可能不直接诱导CP的表达,但CP可能协助Tf/TfR共同完成脑组织内铁的转运。

Objective To observe the dynamic expression of the ferric iron deposit,the transferrin （Tf） /transferrin receptor（TfR） and ceruloplasmin （CP） in different time after ICH and their spatio-temporal patterns. Methods Sprague-Dawley rats received an infusion of Collagenase Ⅳ into the right basal ganglia and were killed at 1,3,7,14 day. MAL-LORY＇ s method was used for ferric iron staining, and brain iron deposits was determined. Brain Tf/TfR/CP around hematoma were examined by immunohistochemistry （IHC）. Results ICH resulted in ferric iron overload in the brain. A marked increase in brain iron was not cleared within 14 days. The expression of Tf in all groups increased and TfK/CP at 1 day,3 day and 7 day intensified in ICH compared with the operation controls, and they reached a plateau at 3 - 7 day in ICH models. Correlation test showed that iron sediment granules positively correlated with Tf/TfR （ r = 0. 468 - 0.521, P 〈 0.01 ） ;CP expression is paralleled with Tf and TfR （ r = 0. 521 - 0. 634 ,P 〈 0.01 ）. Conclusion Iron excessive accumulation after ICH activate Tf/TfR/CP expression. Tf/TfR/CP may play a role in clearing away iron when iron overload in brain.