放射损伤小鼠小肠上皮内淋巴细胞增殖活力变化的实验研究

Changes in proliferative activity of small intestinal intraepithelial lymphocytes after radiation injury in mice

目的：探讨辐射损伤对肠粘膜免疫的影响。方法：小鼠分别受３Ｇｙ、８Ｇｙ、１２Ｇｙ全身照射后８ｈ至１５ｄ６个时相，分离全小肠上皮细胞内淋巴细胞（Ｉｎｔｒａｅｐｉｔｈｅｌｉａｌｌｙｍｐｈｏｃｙｔｅ，ＩＥＬ），用佛波酯、ＣｏｎＡ联合ｒｈＩＬ－２刺激，以３Ｈ－ＴｄＲ参入的计数值反映增殖活力。结果：①３种剂量组ＩＥＬ增殖活力下降明显，都表现出以伤后８ｈ下降，７２ｈ达低值，然后逐渐回升的过程；１２Ｇｙ组的抑制出现更早（８ｈ），程度更重；两种刺激剂的变化态势相同。②正常小鼠分离的ＩＥＬ经体外照射１Ｇｙ～１０Ｇｙ亦导致增殖活力下降；３Ｇｙ和８Ｇｙ同一剂量的整体和离体照射相比较，对增殖活力抑制程度无明显的差异。结论：３种剂量的照射都造成肠粘膜免疫功能的下降。

Objective: To explore the effects of radiation injury on intestinal mucosal immunity. Methods: Kunming strain mice were given whole body irradiation of 60 Co γ ray at doses of 3Gy, 8 Gy and 12 Gy.In the periods of 8 h～72 h and 7 d～15 d after irradiation, IELs were isolated from irradiated mice and stimulated with PMA or ConA in combination with rIL 2 to determine the incorporation of 3H TdR serving as the index to reflect proliferative activity of intestinal intraepithelial lymphocytes. Results:①The amount of 3H TdR incorporation to IELs was gradually decreased with time prolongation. All the 3 groups showed similar type of changes decreasing at 8 h, reaching the lowest level at 48 h～72 h post irradiation, rising again and still not returning to normal on the 15th day. ②The proliferative activity of the IELs isolated from normal mice received 60 Co γ ray at 1 Gy～10 Gy was also decreased.Conclusion: The irradiation at the three doses causes the decrease of intestinal mucosal immunity to result in damage of mucosal immune barrier.