苯并(a)芘诱导小鼠前胃癌模型的建立及共轭亚油酸对其预防作用

目的　用苯并 (a)芘〔B(a)P〕建立小鼠前胃癌模型 ,观察不同构成的共轭亚油酸 (CLA)对前胃癌的抑制作用以及与脂质过氧化的关系。方法　通过灌胃方式给予昆明种小鼠B(a)P ,建立前胃癌模型。用光学显微镜作病理组织检查 ,用比色法测定丙二醛(MDA)含量。结果　利用B(a)P成功地在昆明种小鼠体内建立了前胃癌模型 ,病理结果分析表明所建立的前胃癌为鳞状细胞癌 ;小鼠前胃肿瘤的计数结果表明 ,B (a)P组 ,75 %c9,t11 CLA组 ,98%c9,t11 CLA组 ,98%t10 ,c12 CLA组的肿瘤发生率分别为 10 0 %,75 .0 %,6 9.2 %和 5 3.8%;并且 75 %c9,t11 CLA ,98%c9 ,t11 CLA ,98%t10 ,c12 CLA明显降低前胃肿瘤的直径 ,但对荷瘤小鼠的平均荷瘤数没有影响 ;与阴性对照组和B(a)P对照组相比 ,CLA处理能提高小鼠体内MDA含量。结论　B(a)P诱导昆明种小鼠的前胃组织形成鳞状细胞癌 ;不同构成CLA对B(a)P诱导小鼠前胃癌均具有抑制作用 ,并且MDA可能是CLA发挥预防肿瘤作用的可能机理之一。

Establishment of mouse forestomach neoplasia model induced by benzopyrene and chemopreventive effects of conjugated linoleic acid

AIM To establish mouse forestomach neoplasia model and observe the relation of inhibitory effect on forestomach neoplasm and lipid peroxidation of conjugated linoleic acid(CLA) of different constituent. METHODS Forestomach neoplasm model induced by B(a)P in Kunming mice was established. The numbers of tumor in forestomach and the tumor diameter were counted, and malondialdehyde in mouse plasma was examined by colorimetry. RESULTS 〗The incidence of neoplasm in B(a)P control group，75% c9, t11-CLA group，98% c9, t11-CLA group，98% t10, c12-CLA group was 100%，75.0%，69.2%， 53.8%, respectively; CLA isomers could decrease significantly the average diameter of tumor, but show no effects on the average tumor numbers in tumor-bearing mice; in contrary to salad oil control and B(a) P control group, CLA could increase malondialdehyde in mouse plasma. CONCLUSION Squamous carcinoma was established in mouse forestomach induced by benzopyrene; CLA of different constituent inhibited the formation of forestomach neoplasm and the increased level of malondialdehyde may be one of the mechanisms of the inhibition of CLA on tumor.