Deslauriers R, Somorjai R L, Geoffrion Y, Kroft T, Smith I C, Saunders J K
Division of Biological Sciences, National Research Council of Canada, Ottawa.
NMR Biomed. 1988 Feb;1(1):32-43. doi: 10.1002/nbm.1940010107.
The study was initiated to gain a better understanding of the manifestation of disease in the lipid dynamics in tissue. We have performed high resolution 13C and 1H NMR relaxation measurements on the observable lipid resonances in liver and adipose tissue, excised from mice which were normal fed, normal fasted, and infected with the malarial parasite Plasmodium berghei. We have observed that, although the parasite does not invade the hepatocytes, the composition of the liver lipids changes along with nutritional status and disease state. Analysis of the liver lipids using gas chromatography showed that in all cases studied (normal or malarial, fed or fasted) the phospholipid content of the liver remains constant. The triglyceride content, however, shows an increase of up to fourfold in both 24-hour fasted controls and highly parasitized mice. The fatty acid compositions of the triglycerides in 24-hour fasted normal and highly parasitized mice are altered, when compared with fed controls or with mice having a low level of infection. The unsaturation index increases twofold. The 13C T1 experiments on the methylene and olefinic resonances of liver give a single exponential decay. The value for a particular carbon is independent of the origin of the tissue, the nutritional status or the disease state of the animal. In contrast, both 1H and 13C T2 relaxation of the methylene and olefinic carbon resonances can generally be best analyzed as the sum of two exponential decays (based on an F-test). The 13C T2 values and the pre-exponential weighting factors are independent of the origin of the tissue examined. The T2 data could also be analyzed in terms of a distribution of relaxation times, a physically more realistic model. Lastly, our results suggest that the 1H and 13C resonances of lipids in the cells of diseased or normal liver tissues do not give rise to "long" T2 values, as have been observed in cancer cells with metastatic potential.
开展这项研究是为了更好地了解疾病在组织脂质动力学中的表现。我们对从正常喂食、正常禁食以及感染伯氏疟原虫的小鼠身上切除的肝脏和脂肪组织中可观察到的脂质共振进行了高分辨率的13C和1H NMR弛豫测量。我们观察到，尽管寄生虫不会侵入肝细胞，但肝脏脂质的组成会随着营养状况和疾病状态而变化。使用气相色谱法对肝脏脂质进行分析表明，在所研究的所有情况（正常或疟疾、喂食或禁食）下，肝脏的磷脂含量保持恒定。然而，甘油三酯含量在24小时禁食对照组和高度寄生的小鼠中均显示出高达四倍的增加。与喂食对照组或感染水平较低的小鼠相比，24小时禁食的正常小鼠和高度寄生小鼠中甘油三酯的脂肪酸组成发生了变化。不饱和度指数增加了两倍。对肝脏亚甲基和烯烃共振进行的13C T1实验给出了单指数衰减。特定碳的值与组织的来源、动物的营养状况或疾病状态无关。相比之下，亚甲基和烯烃碳共振的1H和13C T2弛豫通常可以最好地分析为两个指数衰减的总和（基于F检验）。13C T2值和指数前加权因子与所检查组织的来源无关。T2数据也可以根据弛豫时间分布进行分析，这是一个物理上更现实的模型。最后，我们的结果表明，患病或正常肝脏组织细胞中脂质的1H和13C共振不会产生如在具有转移潜能的癌细胞中所观察到的“长”T2值。
