THE TRANSFER OF BICARBONATE BETWEEN THE BLOOD AND TISSUES CAUSED BY ALTERATIONS OF THE CARBON DIOXIDE CONCENTRATION IN THE LUNGS

Abstract

When the alveolar CO2 tension was raised to about 88 mm. by the inhalation of air enriched with CO2, the CO2 combining capacity of the blood was lowered by 2.1 vol. % in dogs and by 4.2 vol. % in cats, as a result of the migration of bicarbonate into the tissue fluid. The time required to bring about equilibrium conditions was less than 5 min. When the alveolar COa tension of dogs was lowered to about 8 mm., the CO2 combining capacity of the blood was increased in some cases by the migration of bicarbonate into the blood, and was diminished in other cases by the migration of bicarbonate out of the blood, the average change being 1.4 vol. % CO2. An hypothesis, based upon the relative CO2 combining capacity of the blood and the tissue fluids, is offered to explain the transfer of bicarbonate between the blood and the tissues.