Uptake of oxygen from the intestine-- experiments with rabbits

Venous portal blood contributes essentially to the oxygen supply of the liver. The effect of oxygen enriched water, applied into the stomach, on oxygenation of portal blood was investigated in rabbits.

15 anaesthetized rabbits were given 30 ml water, containing 45, 80 or 150 mg O2/l, by a gastric tube. Oxygen pressure was monitored continuously by a measuring probe in the stomach, the abdominal cavity and in the gastric as well as in the portal vein.

Intragastrically applied water delivered oxygen slowly, according to the increase in its temperature. The released oxygen was found to penetrate into the abdominal cavity, and a dose-response relationship between oxygen pressure in the stomach and the abdominal cavity was established. 45 mg O2/l water resulted in a negligible increase of oxygen concentration in the abdomen, while 80 or 150 mg O2/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. Oxygen penetration occurred according to the known physical and physiological parameters of gas diffusion. Diffusion of oxygen was enhanced, if concurrently with oxygen the water was enriched with CO2.

Our results show that intragastrically applied oxygenated water with more than 45 mg O2/l delivers O2 into the abdominal cavity and the portal vein. This effect may be of clinical relevance in states of impaired liver perfusion such as fatty liver or hepatitis.