Intestinal absorption and liver uptake of medium-chain fatty acids in non-anaesthetized pigs

Abstract

In order to study the rate of intestinal absorption and hepatic uptake of medium-chain fatty acids (MCFA), six growing pigs, mean body weight 65 kg, were fitted with a permanent fistula in the duodenum and with three catheters in the portal vein, carotid artery and hepatic vein respectively. Two electromagnetic flow probes were also set up, one around the portal vein and one around the hepatic artery. A mixture of octanoic and decanoic acids, esterified as medium-chain triacylglycerols, together with maltose dextrine and a nitrogenous fraction was continuously infused for 1 h into the duodenum. Samples of blood were withdrawn from the three vessels a t regular intervals for 12 h and further analysed for their non-esterified octanoic and decanoic acid contents. The concentration of non-esterified octanoic and decanoic acids in the portal blood rose sharply after the beginning of each infusion and showed a biphasic time-course with two maximum values, one after 15 min and a later one between 75 and 90 min. Only 65 % of octanoic acid infused into the duodenum and 54 % of decanoic acid were recovered in the portal flow throughout each experiment. The amounts of non-esterified MCFA taken up per h by the liver were close to those absorbed from the gut via the portal vein within the same periods of time, showing that the liver is the main site of utilization of MCFA in pigs. These results have been discussed with a special emphasis laid on the possible mechanisms of the biphasic time-course of MCFA absorption and the incomplete recovery in the portal blood of the infused fatty acids.

Portal absorption of 14C after ingestion of spiked milk with 14C-phenanthrene, 14C-benzo[a]pyrene or 14C-TCDD in growing pigs

“…Several authors found relatively constant blood flow values after ingestion of the meal (Guillot et al, 1993;Guillot et al, 1994;Lang et al, 1999). One can easily assume that portal blood flow variations in the present work were similar for all the animals and that they consequently interfered in the same way for all the three diets.…”

“…14 C meal absorption rate was calculated as: "portal absorption of 14 C / 14 C content in the meal". Blood flow per min and per kg body weight could be estimated thanks many references using growing pigs (Rérat et al, 1987;Simoes Nunes et al, 1989;Rérat et al, 1991;Rérat et al, 1992;Guillot et al, 1993;Guillot et al, 1994;Rérat et al, 1996;Santamaria et al, 1997;Lang et al, 1999;Le Floc'h et al, 1999;Vaugelade et al, 2000).…”

45Ca as a marker to assess portal absorption of calcium from milk in the growing pig

“…In fact, it is known that meal ingestion is followed by a small rise in portal blood flow during the first 1-2 postprandial hours and individual variations in pig portal blood flow have been established at between 2.8 and 5.7% [20]. Several authors found relatively constant blood flow values after ingestion of the meal [5,6]. One can easily assume that portal blood flow variations in the present work were similar for all the animals.…”

Effect of High Fat Diet Without Cholesterol Supplementation on Oxidative Stress and Lipid Peroxidation in New Zealand White Rabbits

“…A major proportion of the saturated fats of coconut oil are formed of medium chain fatty acids, which do not require a re-esterification process and are oxidized immediately for energy needs in the liver 1) . Due to this specific characteristic of medium chain fatty acids, it has also been reported that coconut oil cannot be ing oils on risk factors for coronary artery disease, such as oxidative stress and lipid peroxidation in rabbits.…”