Cardiorespiratory functions in mammals are exquisitely sensitive to changes in arterial O2 levels. Hypoxia-inducible factors (e.g., HIF-1 and HIF-2) mediate transcriptional responses to reduced oxygen availability. We demonstrate that haploinsufficiency for the O2-regulated HIF-2α subunit results in augmented carotid body sensitivity to hypoxia, irregular breathing, apneas, hypertension, and elevated plasma norepinephrine levels in adult Hif-2α+/- mice. These dysregulated autonomic responses were associated with increased oxidative stress and decreased mitochondrial electron transport chain complex I activity in adrenal medullae as a result of decreased expression of major cytosolic and mitochondrial antioxidant enzymes. Systemic administration of a membrane-permeable antioxidant prevented oxidative stress, normalized hypoxic sensitivity of the carotid body, and restored autonomic functions in Hif-2α+/- mice. Thus, HIF-2α-dependent redox regulation is required for maintenance of carotid body function and cardiorespiratory homeostasis.
|Original language||English (US)|
|Number of pages||6|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - Feb 15 2011|
- Blood pressure
- Control of ventilation
ASJC Scopus subject areas