[Gasometric changes and acid-base equilibrium of venous blood oxygenated in vitro and incubated with or without a phosphodiesterase inhibitor].

Changes in partial tension of the respiratory gases and in acid-base balance were studied in venous blood subjected to oxygenation, with or without incubation with theophylline. The following modifications were noted: 1) increased pO2; 2) decreased CO2 due to true wash-out caused by tonometry in oxygen; 3)decreased hydrogen ion concentration and bicarbonates following CO2 washing in both experimental models. A smaller reduction in pH and HCO3 was statistically significant in specimens treated with theophylline. This is seen as proof of the view that theophylline inhibits red cell membrane ion exchanges, such as to oppose or at any rate limit metabolic changes in acid-base balance induced by oxygenation.