放烧复合伤后白细胞介素-3基因的表达

为了进一步探讨放射损伤和放烧复合伤引起造血功能障碍的机理，研究了作为造血调控的重要细胞因子——白细胞介素－３（ＩＬ－３）基因在放射损伤、烧伤、放烧复合伤后不同时相点基因表达的变化。方法ｍＲＮＡ抽提、分子杂交、细胞培养、ＩＬ－３生物活性测定、３Ｈ－ＴｄＲ参与实验等生物技术方法。结果放射损伤后ＩＬ－３基因的表达受到明显抑制，照射后第３，１４天表达的ＩＬ－３ｍＲＮＡ减少了７７％，２１％；ＩＬ－３蛋白减少了８３％，３６％。烧伤对ＩＬ－３基因表达的影响呈双相性，烧伤后第３天ＩＬ－３表达受到抑制；烧伤后第１４天ＩＬ－３的表达增强；放烧复合伤后ＩＬ－３的表达受到抑制，其抑制程度介于放射损伤与烧伤之间，各观察组ＩＬ－３基因表达的变化与骨髓有核细胞数的变化呈平行关系。结论放射损伤、放烧复合伤后ＩＬ－３基因表达被抑制可能是急性放射病引起造血功能障碍的原因之一。

Changes of interleukin-3 expression after combined radiation-burn injury in mice

Objective To study the changes of IL 3 expression after 5Gy irradiation, 30% total body surface area burn and combined radiation burn injury in mice. Methods Northern dot blotting, production of mRNA, cell culture, assay of IL 3 biological activity, etc. Results The IL 3 mRNA was markedly decreased by 77% and 21% on the 3rd day and the 14th day after irradiation, respectively. The IL 3 protein was decreased by 83% and 36% on 3rd and 14th day, respectively. There was a significant inhibition of IL 3 expression on the 3rd day after simple burn and slight increase of IL 3 expression on the 14th day. In groups with combined injury, IL 3 was more than that in the irradiated groups but less than that in the groups with burn injury. The changes of IL 3 expression were parallel with the changes of bone marrow cells. Conclusion Inhibition of IL 3 expression is one of the reasons of hematopoietic failure caused by radiation and combined radiation burn injury in mice.