Fig. 2.

Pet_CO2 (left) and V̇i (right) responses from one representative trial of CB inhibition from each dog: dog 1 (A and B), dog 2 (C and D), dog 3 (E and F), and dog 4 (G and H). Data are breath by breath and normalized to control (endogenous CB perfusion; i.e., CB not inhibited). CB inhibition commenced at time 0 (vertical line). Numbers at arrow indicate arterial Pco₂ (Torr) and pH measured at that time. Note that the hypoventilation is maintained throughout CB inhibition, despite marked CO₂ retention and arterial acidosis. Δ, Change.