TY - JOUR

T1 - Size and number of lymph particles measured by a particle sizer during absorption of structured oils in rats

AU - Porsgaard, Trine

AU - Kánský, Jirí

AU - Mason, Sarah Louise

AU - Mu, Huiling

PY - 2005

Y1 - 2005

N2 - Chylomicrons transport absorbed fat from the intestine to the circulation. During dietary fat absorption, the chylomicrons become larger in diameter, and in some studies an increase in chylomicron number has been observed as well. In the present study, we compared particle size and number in rat lymph following administration of four different oils. We administered fish oil, medium-chain TAG (MCT), and two structured oils differing in intramolecular structure, with either medium-chain FA in the outer positions of the TAG and long-chain n-3 PUFA in the sn-2 position (MLM oil) or with the reverse structure (LML oil), to lymph-cannulated rats and collected lymph in fractions for the following 8 h. Chylomicron size was measured by a particle size analyzer immediately after collection, and from these data the number of chylomicrons present was estimated. The number of particles in lymph increased during the absorption of oils containing long-chain PUFA (MLM, LML, and fish oil), whereas it was not affected by administration of MCT. The FA from MCT were probably absorbed via the portal vein; therefore, only a small number of particles were measured in lymph. When comparing the two structured oils, we observed a tendency toward a higher number of particles after LML administration, although the difference was not statistically significant. The highest number of particles after administration of all oils was observed in the size intervals 53-80 and 80-121 nm and probably represented small chylomicrons. Thus, the FA composition influenced the number of particles in lymph during absorption, whereas TAG structure had only a minor influence.

AB - Chylomicrons transport absorbed fat from the intestine to the circulation. During dietary fat absorption, the chylomicrons become larger in diameter, and in some studies an increase in chylomicron number has been observed as well. In the present study, we compared particle size and number in rat lymph following administration of four different oils. We administered fish oil, medium-chain TAG (MCT), and two structured oils differing in intramolecular structure, with either medium-chain FA in the outer positions of the TAG and long-chain n-3 PUFA in the sn-2 position (MLM oil) or with the reverse structure (LML oil), to lymph-cannulated rats and collected lymph in fractions for the following 8 h. Chylomicron size was measured by a particle size analyzer immediately after collection, and from these data the number of chylomicrons present was estimated. The number of particles in lymph increased during the absorption of oils containing long-chain PUFA (MLM, LML, and fish oil), whereas it was not affected by administration of MCT. The FA from MCT were probably absorbed via the portal vein; therefore, only a small number of particles were measured in lymph. When comparing the two structured oils, we observed a tendency toward a higher number of particles after LML administration, although the difference was not statistically significant. The highest number of particles after administration of all oils was observed in the size intervals 53-80 and 80-121 nm and probably represented small chylomicrons. Thus, the FA composition influenced the number of particles in lymph during absorption, whereas TAG structure had only a minor influence.

M3 - Journal article

C2 - 15957253

VL - 40

SP - 273

EP - 279

JO - Lipids

JF - Lipids

SN - 0024-4201

IS - 3

ER -