Effect of dietary fatty acids on jejunal and ileal oleic acid uptake by rat brush border membrane vesicles.
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.
Prieto
R M
RM
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.
Stremmel
W
W
Sales
C
C
Tur
J A
JA
D000818:Animals; D001692:Biological Transport; D000074263:Coconut Oil; D003314:Corn Oil; D004041:Dietary Fats; D007082:Ileum / Q000502:physiology; D007413:Intestinal Mucosa / Q000378:metabolism*; D007583:Jejunum / Q000502:physiology; D008297:Male; D008871:Microvilli / Q000378:metabolism*; D019301:Oleic Acid / Q000378:metabolism*; D010938:Plant Oils; D051381:Rats; D017208:Rats, Wistar; D012450:Safflower Oil
D004041:Dietary Fats; D010938:Plant Oils; D019301:Oleic Acid; D012450:Safflower Oil; D003314:Corn Oil; D000074263:Coconut Oil