The effect of carbonic anhydrase inhibition on the canine in vivo H⁺P_CO2 relationship

The in vivo canine H⁺ -P_CO2 relationship was measured in muscle venous, pulmonary arterial, and arterial blood, at a range of P_CO2 values during hyperventilation, before and following acetazolamide. An increase in slope of the straight line describing this relationship was detected from the muscle venous to the arterial sampling site. Following acetazolamide the muscle venous and pulmonary arterial lines had a similar slope to the unchanged arterial line. The response of the venous lines suggests that carbonic anhydrase plays a significant role in determining the effective _{in vivo} buffering of the venous compartment.