Uptake of oxygen from the intestine - Experiments with rabbits

Background: Venous portal blood contributes essentially to the oxygen suppl y of the liver. The effect of oxygen enriched water, applied into the stoma ch, on oxygenation of portal blood was investigated in rabbits. Material and Methods: 15 anaesthetized rabbits were given 30 ml water, cont aining 45, 80 or 150 mg O-2/l, by a gastric tube. Oxygen pressure was monit ored continuously by a measuring probe in the stomach, the abdominal cavity and in the gastric as well as in the portal vein. Results: Intragastrically applied water delivered oxygen slowly, according to the increase in its temperature. The released oxygen was found to penetr ate into the abdominal cavity, and a dose-response relationship between oxy gen pressure into the stomach and the abdominal cavity was established. 45 mg O-2/l water resulted in a negligible increase of oxygen concentration in the abdomen, while 80 or 150 mg O-2/l lead to an increase of oxygen by 10 rsp. 20 mmHg in the abdomen, and by up to 14 mmHg in the portal vein. Oxyge n penetration occurred according to the known physical and physiological pa rameters of gas diffusion. Diffusion of oxygen was enhanced, if concurrentl y with oxygen the water was enriched with CO2. Conclusions: Our results show that intragastrically applied oxygenated wate r with more than 45 mg O-2/l delivers O-2 into the abdominal cavity and the portal vein. This effect may be of clinical relevance in states of impaire d liver perfusion such as fatty liver or hepatitis.