白细胞介素-6对荷瘤小鼠正常组织的辐射保护效应

以受全身照射的S180肉瘤荷瘤小鼠为研究对象，利用化学比色法测定荷瘤鼠肝脏、脾脏、肾脏、心脏、肺、脑和骨髓组织的活性氧(ROS)、丙二醛(MDA)水平和谷胱苷肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)活性，探讨白细胞介素-6(IL-6)对荷瘤机体正常组织辐射防护效应及机理。结果显示：荷瘤鼠受照射后其肝脏、肾脏、脾脏、骨髓、脑、肺组织匀浆中ROS、MDA含量明显升高，而GSH-Px和CAT活性明显降低，其机制是电离辐射造成抗氧化酶的损伤及机体内自由基含量上升。IL-6能够显著降低受照射荷瘤小鼠肝脏、脾脏、骨髓、脑组织匀浆中活性氧(ROS)、丙二醛(MDA)水平，提高谷胱苷肽过氧化物酶(GSH-Px)和过氧化氢酶(CAT)活性。对肾脏、肺组织匀浆中ROS、MDA含量和GSH-Px、CAT活性无明显影响。本实验提示IL-6通过清除ROS和保护抗氧化酶的损伤起辐射保护作用，IL-6对不同组织细胞辐射保护作用程度不同。是由于机体细胞中IL-6R的数量、亲和力及IL-6信号传导途径存在差异。

The studies on radio-protective effects of IL-6 to normal tissue of irradiated tumor bearing mice

In order to investigate radioprotective effects of interleukin-6 (IL-6) to normal tissues of irradiated tumor-bearing S180 sarcoma mice and its related mechanism, the contents of reactive oxygen species(ROS), malondialdehyde (MDA), activity of glutathione peroxidaes (GSH-Px) and catalase (CAT) in liver, kidney, spleen, lung, brain, marrow were determined. It was found that the content of ROS and MDA increased and the content of GSH-Px and CAT decreased in normal tissues of tumor-bearing S180 sarcoma mice under fractional total-body-irradiation (TB1). With addition of IL-6 the content of ROS and MDA was decreased and the activity of GSH-Px and CAT was increased in liver, spleen, brain, marrow, whereas there is no significant effect on the lung and kidney tissues. It can be deduced that IL-6 has some radio-protective effects to the normal tissue of tumor-bearing mice involved in fractional TBI via scavenging ROS and protecting antioxidant enzymes. As the number, affinity of IL-6 receptor and signal transfer pathway of IL-6 are changeable, the radio-protective effects of IL-6 in various tissues are different.