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EXERCISE AND RESPIRATORY PHYSIOLOGY
1Institute of Veterinary Physiology, Vetsuisse Faculty, and Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland; 2Laboratoire de Physiologie Intégrative Cellulaire et Moléculaire, UMR Centre National de la Recherche Scientifique 5123 Villeurbanne, France; 3Institute of Physiology and ZIHP, University of Zürich, Zürich, Switzerland; and 4Department of Anesthesiology, University of Colorado Denver Health Sciences Center, Denver, Colorado
Submitted 9 December 2007 ; accepted in final form 21 May 2008
Proteins harboring a Per-Arnt-Sim (PAS) domain are versatile and allow archaea, bacteria, and plants to sense oxygen partial pressure, as well as light intensity and redox potential. A PAS domain associated with a histidine kinase domain is found in FixL, the oxygen sensor molecule of Rhizobium species. PASKIN is the mammalian homolog of FixL, but its function is far from being understood. Using whole body plethysmography, we evaluated the ventilatory response to acute and chronic hypoxia of homozygous deficient male and female PASKIN mice (Paskin–/–). Although only slight ventilatory differences were found in males, female Paskin–/– mice increased ventilatory response to acute hypoxia. Unexpectedly, females had an impaired ability to reach ventilatory acclimatization in response to chronic hypoxia. Central control of ventilation occurs in the brain stem respiratory centers and is modulated by catecholamines via tyrosine hydroxylase (TH) activity. We observed that TH activity was altered in male and female Paskin–/– mice. Peripheral chemoreceptor effects on ventilation were evaluated by exposing animals to hyperoxia (Dejours test) and domperidone, a peripheral ventilatory stimulant drug directly affecting the carotid sinus nerve discharge. Male and female Paskin–/– had normal peripheral chemosensory (carotid bodies) responses. In summary, our observations suggest that PASKIN is involved in the central control of hypoxic ventilation, modulating ventilation in a gender-dependent manner.
ventilatory control; hypoxia; gender differences; oxygen sensing; carotid bodies
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