α-ketoglutarate (AKG) absorption from pig intestine and plasma pharmacokinetics

To study the absorption, metabolism and kinetics, the AKG ( in different concentrations) was administered intravenously, intra-portally, orally and directly into the ileum or duodenum of pigs, chronically fitted with portal and jugular catheters and T-shaped cannula at the duodenum and ileum. Additionally, this study was conducted to determine the influence of low pH, Fe2+ or/ and SO42- on AKG gut absorption and conversely FeSO4 and FeSO4/AKG on Fe2+ gut absorption. It is concluded that AKG was significantly better absorbed from the upper small intestine than from the distal sections. Furthermore, low pH, Fe2+ and/or SO42- ions enhanced AKG absorption. The AKG administered to the portal vein was rapidly eliminated from the blood (half-life less than 5 min). The short lifetime for AKG is probably dependent on quick metabolism in the enteorcyetes and liver. However, the prolonged half-life can be related to its low AKG blood concentration. The Fe2+ concentrations in blood increased after FeSO4 and FeSO4/AKG duodenal infusion. The implication of above observations is important for practical application of the AKG in animal and human nutrition as well in medicine.