外源RNA促进小鼠肠腺辐射损伤恢复的研究

RESTORATIVE EFFECT OF EXOGENOUS RNA ON THE INTESTINAL CRYPTS IN MICE AFTER ABDOMINAL γ-IRRADIATION

ＢＡＬＢ／ｃ小鼠接受１０４０ｃＧｙ６０Ｃｏγ射线腹部照射后，采用不同来源的ＲＮＡ、不同的注入剂量、途径、时间和次数等因素，研究外源ＲＮＡ对空肠肠腺存活率的影响。结果表明：（１）不同来源的ＲＮＡ均可明显提高受照小鼠的肠腺存活率。（２）酵母ＲＮＡ的注入剂量与肠腺存活率之间呈一钟形曲线，局部肠腔注入的最适剂量为４０～６０μｇ／小鼠，腹腔和肌肉注入时均为８０μｇ／小鼠。（３）采用从（静脉、腹腔、肌肉和皮下）不同途径注入酵母ＲＮＡ，均可显著提高受照小鼠的肠腺存活率，其中静脉注入效果最佳。（４）照射后小鼠的肠腺存活率随注入酵母ＲＮＡ时间的推迟而降低，两者在半对数坐标上呈线性关系。（５）小鼠于照射后６ｈ内１次注入ＲＮＡ，即可生效，多次注入并不增加其疗效。

Our previous investigtion revealed a restorative effect of exogenous nucleic acids on the intestinal crypt in mice after abdominal V--irradiation. In this article,the factors influencing the restorative effect of exogenous RNA on the intestinal crypt in mice post--irradiation were studied. The results showed that=(a) RNAs from different sources all showed the crypt survival enhancement capability.(b) Bell--shaped curves correlating the crypt survival fraction and RNA doses were obtained, with the optimal doses for different routes of administration estimated.(c) Comparing the different routes of RNA administration, the intravenous injection seemed to be the most effective. (d) An exponential relationship between the crypt survival fraction and the post--irradiation time of RNA administration was found.The earlier the administration, the more effective it was. (e) Administration of RNA merely once within 6 h after irradiation, the increases of crypt survival fraction was statistically significant when compared with that of the irradiated control.