Peripheral and central chemoreceptor control of ventilation during exercise in humans

Area of Science:

• Human physiology
• Respiratory control
• Exercise science

Background:

• Arterial blood gas homeostasis during exercise suggests humoral ventilatory control.
• The precise roles of central and peripheral chemoreflexes in this control are debated.
• Current chemoreflex sensitivity estimations face technical and interpretational challenges.

Purpose of the Study:

• To elucidate the distinct contributions of central and peripheral chemoreceptors to ventilatory control during exercise.
• To address the controversy surrounding chemoreflex involvement in humoral ventilatory regulation.
• To clarify chemoreceptor function across different exercise intensities and acid-base conditions.

Main Methods:

• Analysis of existing evidence and literature on chemoreceptor function during exercise.
• Evaluation of technical limitations in estimating chemoreflex sensitivity.
• Interpretation of physiological data related to cerebrospinal fluid pH and metabolic acidemia.

Main Results:

• Central chemoreceptors contribute minimally during moderate exercise due to stable cerebrospinal pH.
• Central chemoreceptors limit hyperpnea during high-intensity exercise, aiding respiratory compensation for acidemia.
• Peripheral chemoreceptors significantly influence ventilatory responses during moderate exercise onset but are less critical in steady-state.
• Peripheral chemoreceptors drive substantial respiratory compensation during high-intensity exercise.

Conclusions:

• Central chemoreceptors are primarily involved in regulating ventilation during high-intensity exercise and chronic acidemia.
• Peripheral chemoreceptors are key drivers of ventilatory adjustments during the initial phase of moderate exercise.
• Understanding chemoreceptor roles is vital for comprehending human exercise physiology and ventilatory control.