Developmental influences on carotid body responses to hypoxia.

Progress on our understanding of the mechanisms by which ventilatory responses to hypoxia and hypercapnia mature following birth will be reviewed. New reports have broadened the current understanding of these mechanisms, especially those relating to maturation of the arterial chemoreceptors in the carotid body. However, a clear understanding of the physiologic, morphologic, neurochemical and molecular developmental events remains elusive. Of particular interest is the change in carotid body sensitivity to oxygen in the first days following birth. Further, perinatal hypoxia or hyperoxia results in blunted hypoxic chemosensitivity in premature infants with chronic lung disease and in various animal models. Hence, cellular and molecular mechanisms altering the normal maturational progression will also be discussed.