Elizondo Alejandra, Araya Julia, Rodrigo Ramón, Poniachik Jaime, Csendes Attila, Maluenda Fernando, Díaz Juan C, Signorini Cinzia, Sgherri Cristiana, Comporti Mario, Videla Luis A
Department of Nutrition, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago, Chile.
Obesity (Silver Spring). 2007 Jan;15(1):24-31. doi: 10.1038/oby.2007.518.
Our aim was to study the fatty acid (FA) composition of liver phospholipids and its relation to that in erythrocyte membranes from patients with obese nonalcoholic fatty liver disease (NAFLD), as an indication of lipid metabolism alterations leading to steatosis.
Eight control subjects who underwent antireflux surgery and 12 obese patients with NAFLD who underwent subtotal gastrectomy with a gastro-jejunal anastomosis in Roux-en-Y were studied. The oxidative stress status of patients was assessed by serum F2-isoprostanes levels (gas chromatography/negative ion chemical ionization tandem mass spectrometry). Analysis of FA composition of liver and erythrocyte phospholipids was carried out by gas-liquid chromatography.
Patients with NAFLD showed serum F2-isoprostanes levels 84% higher than controls. Compared with controls, liver phospholipids from obese patients exhibited significantly 1) lower levels of 20:4n-6, 22:5n-3, 22:6n-3 [docosahexaenoic acid (DHA)], total long-chain polyunsaturated FA (LCPUFA), and total n-3 LCPUFA, 2) higher 22:5n-6 [docosapentaenoic acid (DPAn-6)] levels and n-6/n-3 LCPUFA ratios, and 3) comparable levels of n-6 LCPUFA. Levels of DHA and DPAn-6 in liver were positively correlated with those in erythrocytes (r = 0.77 and r = 0.90, respectively; p < 0.0001), whereas DHA and DPAn-6 showed a negative association in both tissues (r = -0.79, p < 0.0001 and r = -0.58, p < 0.01, respectively), associated with lower DHA/DPAn-6 ratios.
Obese patients with NAFLD showed marked alterations in the polyunsaturated fatty acid pattern of the liver. These changes are significantly correlated with those found in erythrocytes, thus suggesting that erythrocyte FA composition could be a reliable indicator of derangements in liver lipid metabolism in obese patients.
我们的目的是研究肥胖非酒精性脂肪性肝病（NAFLD）患者肝脏磷脂的脂肪酸（FA）组成及其与红细胞膜中FA组成的关系，以此作为导致脂肪变性的脂质代谢改变的指标。
对8例接受抗反流手术的对照受试者和12例接受Roux-en-Y胃空肠吻合术的肥胖NAFLD患者进行了研究。通过血清F2-异前列腺素水平（气相色谱/负离子化学电离串联质谱法）评估患者的氧化应激状态。采用气液色谱法分析肝脏和红细胞磷脂的FA组成。
NAFLD患者血清F2-异前列腺素水平比对照组高84%。与对照组相比，肥胖患者的肝脏磷脂呈现出显著差异：1）20:4n-6、22:5n-3、22:6n-3[二十二碳六烯酸（DHA）]、总长链多不饱和脂肪酸（LCPUFA）和总n-3 LCPUFA水平较低；2）22:5n-6[二十二碳五烯酸（DPAn-6）]水平和n-6/n-3 LCPUFA比值较高；3）n-6 LCPUFA水平相当。肝脏中DHA和DPAn-6的水平与红细胞中的水平呈正相关（分别为r = 0.77和r = 0.90；p < 0.0001），而DHA和DPAn-6在两种组织中呈负相关（分别为r = -0.79，p < 0.0001和r = -0.58，p < 0.01），且DHA/DPAn-6比值较低。
肥胖NAFLD患者肝脏的多不饱和脂肪酸模式出现明显改变。这些变化与红细胞中的变化显著相关，因此表明红细胞FA组成可能是肥胖患者肝脏脂质代谢紊乱的可靠指标。
