Fig. 3.

Ventilatory response to altered levels of oxygen. A–C: oxyhemoglobin saturation ($\text{S}{\text{a}}_{{\text{O}}_2}$), oxygen tension (Po₂), and arterial oxygen tension ($\text{P}{\text{a}}_{\text{O}}{}_{{}_2}$). V̇_E, ventilation. HAH, high-affinity hemoglobin. *P < 0.05, significantly different slope than controls.