Stimulus Interaction between Hypoxia and Hypercapnia in the Human Peripheral Chemoreceptors

Abstract

The combined effects of hypoxia and hypercapnia on ventilation were demonstrated synergistic in mammalian. ( Neilson 1952). Although stimulus interaction between hypoxia and hypercapnia in peripheral chemoreceptors has been clearly demonstrated in experimental animals, there have been limited studies targeted in human. It is difficult to distinguish peripheral chemoreception from central chemoreception in steady-state ventilatory response to hypercapnia, since inspired hypercapnic gas stimulates both peripheral and central chemoreceptor. On the contrary, “two breaths method” has been used to estimate the peripheral chemoreceptor activity in human. In this method, transient alteration of ventilation with two breaths of hypoxic gas or hypercapnic gas may show the peripheral chemoreceptor activity. In the present study, we evaluate the ventilatory response to combined effects of hypoxia and hypercapnia in the peripheral chemosensitivity in healthy human by using two breaths method.