Effects of an allosteric hemoglobin affinity modulator on arterial blood gases and cardiopulmonary responses during normoxic and hypoxic low-intensity exercise

In humans, a novel allosteric hemoglobin-oxygen affinity modulator was administered to comprehensively examine the cardiopulmonary consequences of stabilizing a portion of the available hemoglobin in a high-oxygen affinity state during submaximal exercise in normoxia and hypoxia. Oral administration of voxelotor enhanced arterial oxygen saturation during submaximal exercise without altering oxygen consumption and central hemodynamics; however, the partial pressure of arterial carbon dioxide was reduced and the partial pressure of arterial oxygen was increased implying that hyperventilation also contributed to the increase in oxygen saturation. The preservation of arterial oxygen saturation and content was particularly evident during hypoxic submaximal exercise, when arterial desaturation typically occurs, but this did not influence arterial-venous oxygen difference.