氨磷汀对荷瘤鼠放疗后肿瘤保护作用

目的探讨氨磷汀对C57BL／6荷瘤鼠放疗后肿瘤组织的保护作用及其对放疗效果的影响。方法培养Lewis肺癌细胞株，传代，制成单细胞悬液，调整细胞密度至10。／L，小鼠右下肢皮下注射制备荷瘤鼠模型。随机分为放疗＋氨磷汀组（A组）、放疗组（B组）、氨磷汀组（c组）、对照组（D组），各8只。放疗前给予A组、c组荷瘤鼠腹腔注射5mL氨磷汀溶液（8g／L），B组、D组给予同等剂量生理盐水腹腔注射，30min后A组、B组荷瘤鼠局部照射6MV的x线10Gy。每2d测量小鼠体质量及肿瘤体积；15d后处死小鼠，TUNEL法检测肿瘤细胞凋亡率。结果A、B、c、D组小鼠各时间点体质量差异均无显著意义（P〉0．05）。第1天4组荷瘤鼠肿瘤体积比较差异无显著意义（P〉0．05），第3～13天A组肿瘤体积较其他3组减小，B组肿瘤体积较c、D组减小，差异有显著意义（F=4．290～15．470，P＜0．05）；A组与B组比较、C组与D组比较，差异无显著意义（P〉0．05）。A组肿瘤细胞凋亡率高于其他3组，B、C组高于D组，差异均有显著意义（F=36．535，P〈0．01）；B组、C组比较，差异无显著意义（P〉0．05）。结论氨磷汀对肿瘤组织没有明显的保护作用，不影响放疗效果；氨磷汀可能具有促进肿瘤细胞凋亡的作用。

THE PROTECTIVE EFFECT OF AMIFOSTINE ON TUMOR IN CANCER-BEARING MICE AFTER RADIOTHERAPY

Objective To explore the protection effect of Amifostine （AMI） on tumor tissues in cancer-bearing mice after radiotherapy （RT） and its influence on efficacy of the therapy. Methods A cultivation and passage of Lewis lung cancer lines were carried out, and single-cell suspension made, the cell density was then modulated to 106/L and subcutaneously injected to right lower limb to create a cancer-bearing model in mice. The mice were randomized to four groups as group A （AMI＋RT）, group B （RT）, group C （AMI）, and control group, with eight mice in each group. Before radiotherapy, an intraperitoneal injection of 5 mL （8 g/L） AMI was offered to the mice in group A and group C, a same dose of normal saline was given to those in group B and control group, 30 minutes later, the mice in groups A and B received local irradiation （6 MV-X, 10 Gy）. The body weight and gross tumor volume were measured every two days. Fifteen days later, the mice were sacrificed for detecting apoptosis of tumor cells using TUNEL method. Results The differences of body weight between the mice in the four were not significant （P〉 0.05）. On the first day, tumor volume in the mice between the four groups were not significantly different （P〉0.05）, on days 3 to 13, the tumor volume in the mice of group A was decreased versus the other three groups, and that in group B was smaller than that in groups C and D, the differences being significant （F = 4.290-15.470, P 〈0.05）, and the difference between groups A and B, as well as C and D, no significant differences were noted （P〉0.05）. The cell apoptosis in group A was higher than that in the other three groups, and that in groups B and C was higher than that in group D, the differences were significant （F = 36.535,P〈 0.01）, and the difference of that between groups B and C was not significant （P〉0.05）. Conclusion Amifostine does not pro- tect tumor tissues and affect the efficacy of radiotherapy. It＇s likely that Amifostine has an action to promote apoptosis of tumor cells.