Oxygen Consumption by Acidified Tissues

Abstract

Amberson, Armstrong and Root 1 have described a curious phenomenon; the persistence of oxygen consumption without carbon dioxide production in acidified tissues. Funduhts eggs, for instance, continued to take up some 7 to 14% of the oxygen which they had previously been consuming in normal respiration. This residual oxygen-uptake persisted after neutralization of the acid, and was not affected by KCN or by high temperatures.

In recent experiments 2 on the respiration and respiratory quotient of the embryo and the extra-embryonic membranes of the hen's egg, a similar phenomenon has been observed. These experiments were carried out in Warburg manometers fitted with the cups designed by Dickens and Simer, 3 and the procedure in determining a respiratory quotient was essentially that laid down by the latter investigators. Three manometers are used, 2 of which contain similar pieces of tissue, while the third contains the solutions alone. The cups have an annular trough containing baryta, and a side-bulb containing 2.5N HCl. Manometer 1 gives the oxygen-uptake of its tissue by a steadily increasing negative pressure, and when the acid is tipped at the end of the experiment, the carbon dioxide due to respiration, that bound in the tissue at the beginning, and that contained in the solutions, give together a large positive pressure. The 2 non-respiratory quotas of carbon dioxide are given by manometers 2 and 3 respectively, which are tipped at the beginning of the experiment and show, in one case, the carbon dioxide of tissue and solutions together, in the other case, the carbon dioxide of solutions alone.

The phenomena here reported were often seen in manometer 2, for although respiration was expected to cease on acidification, it was common, though by no means invariable, to note a continuous small development of negative pressure.