Bell J D, Barnard M L, Parkes H G, Thomas E L, Brennan C H, Cunnane S C, Dagnelie P C
NMR Unit, Hammersmith Hospital, London, United Kingdom.
J Lipid Res. 1996 Aug;37(8):1664-74.
The effects of fish oil supplementation (14.5 g n-3 fatty acids/day) on plasma lipoprotein particles in healthy volunteers were assessed by high resolution 13C and 1H nuclear magnetic resonance (NMR) spectroscopy. Resonances not previously observed in the 13C and 1H spectra of plasma and isolated lipoproteins were detected after fish oil ingestion. The 13C resonances, centered at 14.3, 127.1, and 131.6 ppm, have been assigned to specific carbon groups (CH3-CH2-CH = CH-, CH3-CH2-CH = CH-CH2-, CH3-CH2-CH = CH-CH2-, respectively) in eicosapentaenoic acid (C20:5n-3) and docosahexaenoic (C22:6n-3) DHA. The new lipid resonance observed in the 1H spectra of plasma (0.941 ppm) is consistent with the incorporation of these n-3 fatty acids into lipoprotein particles. The presence of increased EPA and DHA in plasma lipids was confirmed by gas-liquid chromatography. A marked reduction in the intensity of the methylene signal from very low density lipoproteins (VLDL) was also observed with fish oil. This reduction arises from a decrease in plasma triglyceride concentration (ca. 18%) and a reduction in the number of VLDL particles. Transverse relaxation studies of isolated VLDL and low density lipoprotein (LDL) showed significant elevation in the T2 of the -(CH2)n- and CH3- signals from non-n-3 fatty acids. The relaxation characteristics and signal intensity of the novel 1H peak (0.941 ppm) point to the existence of n-3 enriched microenvironments within lipoprotein particles. These findings suggest that incorporation of EPA and DHA into VLDL and LDL, after fish oil ingestion, leads to significant alteration in the molecular architecture of lipoprotein particles.
通过高分辨率碳 - 13（13C）和氢 - 1（1H）核磁共振（NMR）光谱法评估了鱼油补充剂（14.5克n - 3脂肪酸/天）对健康志愿者血浆脂蛋白颗粒的影响。在摄入鱼油后，检测到了先前在血浆和分离的脂蛋白的13C和1H光谱中未观察到的共振信号。以14.3、127.1和131.6 ppm为中心的13C共振信号，分别被归属于二十碳五烯酸（C20:5n - 3）和二十二碳六烯酸（DHA，C22:6n - 3）中的特定碳基团（CH3 - CH2 - CH = CH - 、CH3 - CH2 - CH = CH - CH2 - 、CH3 - CH2 - CH = CH - CH2 - ）。在血浆的1H光谱中观察到的新脂质共振信号（0.941 ppm）与这些n - 3脂肪酸掺入脂蛋白颗粒一致。气液色谱法证实了血浆脂质中二十碳五烯酸（EPA）和二十二碳六烯酸（DHA）含量的增加。同时还观察到，鱼油使极低密度脂蛋白（VLDL）中亚甲基信号的强度显著降低。这种降低源于血浆甘油三酯浓度的降低（约18%）以及VLDL颗粒数量的减少。对分离的VLDL和低密度脂蛋白（LDL）进行的横向弛豫研究表明，来自非n - 3脂肪酸的 - (CH2)n - 和CH3 - 信号的T2显著升高。新的1H峰（0.941 ppm）的弛豫特性和信号强度表明脂蛋白颗粒内存在富含n - 3的微环境。这些发现表明，摄入鱼油后，EPA和DHA掺入VLDL和LDL会导致脂蛋白颗粒的分子结构发生显著改变。
