低剂量辐射诱导免疫适应性反应的最佳时间

本实验观察了低剂量Ｘ射线全身单次照射诱导昆明小鼠免疫适应性反应的最佳时间．证实当预照射剂量（Ｄ＿１剂量）为７５ｍＧｙ．剂量率１２．５ｍＧｙ／ｍｉｎ，损伤剂量（Ｄ＿２剂量）为１．５Ｇｙ，剂量率０．３３Ｇｙ／ｍｉｎ，Ｄ＿１与Ｄ＿２间隔６ｈ可诱导脾细胞对脂多糖反应的适应性反应，Ｄ＿１与Ｄ＿２间隔１２ｈ可诱导胸腺细胞自发增殖及脾细胞对ＣｏｎＡ及脂多糖反应的适应性反应．以上结果表明，当Ｄ＿２为１．５Ｇｙ时。７５ｍＧｙ诱导上述免疫适应性反应的最佳时间间隔为６ｈ及１２ｈ．

Optimal time interval for induction of immunologic adaptive response

The optimal time interval between prior dose (DI ) and challengedose (DZ ) for the induction ofimmunologic adaptive response wasinvestigated' Kunming mice were exposed tO 75 AGe X~rays'at a dose rateof i2'5 mGy/min'3, 6. 12, 24. or 60h after the prior irradiatioll the micewere challenged with a dose of 1'5Gy at a dose rate of 0' 33 Gy/min. 18hafter DZ,the mice were sacrificed forexamination of imrnunological parameters. The results showed that withan interval of 6 h between DI andD2, the adaptive. response of thereaction of splenocytes to LPS wasinduced, and with an interval of 12hthe adaptive re$ponses of spontaneous incorporation of sH--TdR intothymocytes and the reaction of splenocytes to Con A and LPS were induced with 75. AGe:prior irradiation.Our data suggested that the optimaltime intervals between DI and DZfor the induction of immunologicadaptiye response were G h and 12 hwith a DI of 75 mGy and a DZ of1 '5 Gy' The mechanism of itnmunologic adaptation following foxy doseradiation is discussed'