Banni S, Evans R W, Salgo M G, Corongiu F P, Lombardi B
Department of Pathology, School of Medicine, University of Pittsburgh, PA.
Carcinogenesis. 1990 Nov;11(11):2047-51. doi: 10.1093/carcin/11.11.2047.
It has been postulated that the hepatocarcinogenicity of a choline-devoid diet in rats stems from peroxidation of liver lipids. We have investigated whether the diet contains conjugated dienes that could account directly for those detected in liver lipids of rats fed a choline-devoid diet. Analyses were performed on samples of corn oil and of a partially hydrogenated fat used to prepare semipurified choline-devoid and choline-supplemented diets, and on fat extracted from two pairs of diets, one set containing 5% corn oil and 10% partially hydrogenated fat, and the other only corn oil (15%). The analyses consisted of quantitation of conjugated dienes by UV spectrophotometry, separation of fatty acids with conjugated dienes by HPLC, and quantitation of trans fatty acids by IR spectrophotometry. Small levels of conjugated diene and trans fatty acids were present in the corn oil, but much higher amounts were found in the partially hydrogenated fat. HPLC analysis yielded distinct elution profiles for the fatty acids with conjugated dienes present in the two fats, and similar results were obtained with fat extracted from the diets. However, no differences were observed between choline-devoid and control choline-supplemented diets. The results indicate that caution must be exercised in interpreting data from UV analysis of tissue lipids of rats fed diets containing a partially hydrogenated fat.
据推测，大鼠缺乏胆碱的饮食的致癌性源于肝脏脂质的过氧化作用。我们研究了这种饮食中是否含有共轭二烯，这些共轭二烯可以直接解释在喂食缺乏胆碱饮食的大鼠肝脏脂质中检测到的那些物质。对玉米油样本和用于制备半纯化缺乏胆碱和补充胆碱饮食的部分氢化脂肪样本进行了分析，还对从两对饮食中提取的脂肪进行了分析，其中一对饮食含有5%的玉米油和10%的部分氢化脂肪，另一对只含有玉米油（15%）。分析包括通过紫外分光光度法定量共轭二烯，通过高效液相色谱法分离含有共轭二烯的脂肪酸，以及通过红外分光光度法定量反式脂肪酸。玉米油中存在少量的共轭二烯和反式脂肪酸，但在部分氢化脂肪中发现的含量要高得多。高效液相色谱分析得出了两种脂肪中含有共轭二烯的脂肪酸的不同洗脱图谱，从饮食中提取的脂肪也得到了类似的结果。然而，在缺乏胆碱的饮食和对照补充胆碱的饮食之间没有观察到差异。结果表明，在解释喂食含有部分氢化脂肪饮食的大鼠组织脂质的紫外分析数据时必须谨慎。
