Carbon Dioxide, Oxygen, and Acidity: The Interaction and Independent Effects on Breathing of These factors in the Arterial Blood.

Abstract

experiments were conducted on pentobarbital anesthetized dogs and on trained unanesthetized dogs to determine the independence or degree of interaction among the three chemical stimuli: O2, CO2, and H+ (measured in arterial blood) as respiratory stimulants. The interaction of the CO2-H+ complex and low oxygen, as described by others, was reconfirmed. Further dissection of this relationship indicated that the interaction between CO2 and O2 and H+ is not involved. The interaction of CO2 and H+ was determined with oxygen tension held above 200 mm Hg, at which level it is unimportant as a respiratory stimulant. It appears that the response to CO2 decreases as the level of H+ increases and vice versa. We interpret this as a negative interaction between these two chemical agents.