Oxygenogenesis, a defence mechanism of the newt for surviving anoxic stress.

At 8°C specimens of Triturus carnifex, isolated in a respiratory chamber containing water with 1.3 ppm of oxygen, completely consumed it in little over an hour; yet, even after 48 hours of anoxia, the oxygen pressure in blood sampled from the arterial cone never fell below 30% of that recorded in normoxic controls. The permanence of oxygen in the blood, incompatible with the condition of anoxia, demonstrates that there must be a physiological mechanism that produces the molecule. The liver, on account of its mass and histological structure, is the only possible seat of this process. With the supplement of anaerobic glycolysis, the oxygen produced allows the animal to survive for long periods in totally anoxic environments, a phenomenon already observed in other lower vertebrates but until now explained by glycolysis alone. Further experimental data indicate that haemolysis and hepatic melanogenesis are essential in promoting and inactivating oxygenogenesis respectively.