Prieto R M, Stremmel W, Sales C, Tur J A
Universitat de les Illes Balears, Departament de Biologia Fonamental i Ci-encies de la Salut, Ctra. de Valldemossa km 7.5, Palma de Mallorca E-07071, Spain.
Eur J Med Res. 1996 Apr 18;1(7):355-60.
To test the effect of dietary fatty acids on fatty acid uptake, the influx kinetics of a representative long-chain fatty acid, 3H-oleic acid, in both the jejunum and ileum of rats has been studied using brush border membrane vesicles (BBMV). Animals were fed with semipurified diets containing 5 g fat/100 g diet, as corn oil (control group), safflower oil (unsaturated group) and coconut oil hydrogenated (saturated group). With increasing unbound oleate concentration in the medium, the three dietary groups showed saturable kinetics in both jejunal and ileal BBMV (controls: Vmax = 0.15 +/- 0.01 nmol x mg protein-1 x 5 min-1 and Km = 136 +/- 29.1 nmol for jejunum, and Vmax = 0.23 +/- 0.03 nmol x mg protein-1 x 5 min-1 and Km = 196 +/- 50.3 nmol for ileum; unsaturated: Vmax = 0.28 +/- 0.05 nmol x mg protein-1 x 5 min-1 and Km = 242.7 +/- 91.8 nmol for jejunum, and Vmax = 1.29 +/- 0.06 nmol x mg protein-1 x 5 min-1 and Km = 509.8 +/- 97.5 nmol for ileum; saturated: Vmax = 0.03 +/- 0.01 nmol x mg protein-1 x 5 min-1 and Km = 124.5 +/- 72.6 nmol for jejunum, and Vmax = 0.04 +/- 0.01 nmol x mg protein -1.5 min-1 and Km = 205.6 +/- 85.3 nmol for ileum). These results support the theory that feeding an isocaloric diet containing only unsaturated fatty acids enhanced oleic acid uptake, and feeding an isocaloric diet containing only saturated fatty acids decreased oleic acid uptake. The results obtained in the present work also show the adaptative ability of jejunum and ileum to the type of dietary fat.
为了测试膳食脂肪酸对脂肪酸摄取的影响，使用刷状缘膜囊泡（BBMV）研究了代表性长链脂肪酸3H-油酸在大鼠空肠和回肠中的流入动力学。给动物喂食含有5g脂肪/100g饲料的半纯化日粮，分别为玉米油（对照组）、红花油（不饱和组）和氢化椰子油（饱和组）。随着培养基中游离油酸浓度的增加，三个日粮组在空肠和回肠BBMV中均表现出饱和动力学（对照组：空肠的Vmax = 0.15±0.01 nmol x mg蛋白-1 x 5 min-1，Km = 136±29.1 nmol；回肠的Vmax = 0.23±0.03 nmol x mg蛋白-1 x 5 min-1，Km = 196±50.3 nmol；不饱和组：空肠的Vmax = 0.28±0.05 nmol x mg蛋白-1 x 5 min-1，Km = 242.7±91.8 nmol；回肠的Vmax = 1.29±0.06 nmol x mg蛋白-1 x 5 min-1，Km = 509.8±97.5 nmol；饱和组：空肠的Vmax = 0.03±0.01 nmol x mg蛋白-1 x 5 min-1，Km = 124.5±72.6 nmol；回肠的Vmax = 0.04±0.01 nmol x mg蛋白-1 x 5 min-1，Km = 205.6±85.3 nmol）。这些结果支持了以下理论：喂食仅含不饱和脂肪酸的等热量日粮可增强油酸摄取，而喂食仅含饱和脂肪酸的等热量日粮则会降低油酸摄取。本研究获得的结果还表明空肠和回肠对膳食脂肪类型的适应能力。
