| 1. |
- Melin, Tor, et al.
(författare)
-
Absorption and metabolism of orally fed arachidonic acid and linoleic acid in the rat.
- 1988
-
Ingår i: American Journal of Physiology: Gastrointestinal and Liver Physiology. - 1522-1547. ; 255:5 Pt 1, s. 612-618
-
Tidskriftsartikel (refereegranskat)abstract
- [3H]arachidonic [( 3H]20:4) and [14C]linoleic acid [14C]18:2) were fed to rats in Intralipid or cream. Later (30-240 min) the stomach, small intestine, plasma, and liver were analyzed for radioactivity in different lipid classes. [3H]20:4 and [14C]18:2 were emptied from the stomach and absorbed by the intestine at similar rates. The [3H]20:4:[14C]18:2 ratio of the lipids in the small intestinal wall increased, however, with time. This was due to a higher retention of [3H]20:4 than [14C]18:2 in intestinal phospholipids. In contrast, more of the [14C]18:2 was in triacylglycerol of the small intestine and plasma. The highest 3H:14C ratios were found in phosphatidylethanolamine and phosphatidylinositol. The 3H:14C ratio of intestinal phosphatidylcholine varied with the type of fat vehicle used, being highest in the Intralipid experiments. After feeding Intralipid (30-60 min), significantly more of the plasma [3H]20:4 than plasma [14C]18:2 was in diacylglycerol, the 3H:14C ratio of which was much higher than that of plasma free fatty acids. [3H]20:4 and [14C]18:2 of chyle triacylglycerol are thus metabolized differently.
|
|
| 2. |
- Nilsson, Åke, et al.
(författare)
-
Absorption and lymphatic transport of exogenous and endogenous arachidonic and linoleic acid in the rat
- 1987
-
Ingår i: American Journal of Physiology: Gastrointestinal and Liver Physiology. - 1522-1547. ; 252:6, s. 817-824
-
Tidskriftsartikel (refereegranskat)abstract
- [3H]Arachidonic (20:4) and [14C]linoleic acid (18:2) were fed to thoracic duct-cannulated rats in test meals of either tracers alone, cream, Intralipid, pure arachidonic acid, or pure linoleic acid. Less [3H]20:4 than [14C]18:2 was recovered in chyle during the first 5 h. After cream feeding, the proportion of radioactivity found in phospholipids was high and increased during the first 3 h. After the meal (3-5 h) 61 +/- 6% of the 3H and 57 +/- 10% of the 14C was in phosphatidylcholine, and 11 +/- 3% of the 3H and 3.0 +/- 4% of the 14C was in phosphatidylethanolamine. Changing the fat vehicle to Intralipid or pure 18:2 decreased the proportion of label in the phospholipids and increased the 3H and 14C radioactivity in the triacylglycerol fraction, the distribution of 14C being influenced more than that of 3H. After feeding the tracers in 200 microliters of pure 20:4, greater than 90% of both isotopes was in triacylglycerol. During fasting, triacylglycerol transported 56% (0.7 mumol/h), phosphatidylcholine transported 34% (0.4 mumol/h), and phosphatidylethanolamine transported 10% (0.1 mumol/h) of the 20:4 mass. After cream or Intralipid feeding, the output of 20:4-containing phosphatidylcholine and phosphatidylethanolamine increased 2.1- to 2.8-fold, whereas the transport of 20:4 with triacylglycerol remained constant. Phospholipids thus became the predominant transport form for 20:4. After feeding 200 microliters of 20:4, the intestine produced, however, 20:4-rich triacylglycerols that transported 89% of the chyle 20:4
|
|
