香烟对阻止黄曲霉素B_1诱致小白鼠癌前病变影响的肝细胞核内DNA定量研究

Effect of Tobacco Smoke on DNA Content of AFB_1-Induced Precancerous Cells

本文将津白2纯系小白鼠60只.随机等数分三组:AFB_1组、AFB_1+香烟熏组和对照组。AFB_1溶于DMSO.5μg/每日/每只量拌于饲料投食,熏烟组以30g/日烟丝熏烟,经半年实验,肝H.E常规切片.发现两实验组.肝细胞有不典型增生,程度难确定,电镜下.肝细胞主要为变质及轻度胶原增生。但肝印片置Leitz MPV Ⅲ型测定肝细胞核DNA含量,发现三组均属多峰型,对照组与AFB_+烟熏组主峰相当4C处.AFB_1组则在8C处.两实验组间从多倍体与异倍体数量看,则有显著差别(P<0.05).证实AFB_1+烟熏组具有阻止AFB_1诱致小白鼠肝癌变的作用。

In this study, 60 pure bred mice were divided into three groups, 20 each: (1) Control group, (2) AFB1-infected group,and (3)AFB, plus tobacco smoking group. Crystalline AFB1 was dissolved in DMSO and fed the experimental mice. Tissue slides were fixed in Carnoy' s solution and stained with Feulgen' s reaction. The results showed that there were significant differences in total nuclear areas among the three groups. The patterns of histogram for nuclear DNA content were different among these groups. Routine sections stained with H. E. of the latter two experimental groups showed precancerous changes in liver cells which were not distinguishable in degree under light microscopy. In conclusion , cigarette smoking might be protective against AFB1 -induced primary cancer of the liver in mice.