Different roles of oxygen-sensing proteins in the rat breathing control during ongoing and repeated low oxygen conditions

HIF-1alpha expression in the carotid body does not increase during intermittent hypoxia, contrasting with responses observed in chronic hypoxia.

• The carotid body plays a role in cardiovascular issues related to sleep-disordered breathing.
• Increased carotid body volume and HIF-1alpha expression were noted in chronic hypoxia but not in intermittent hypoxia.
• HIF-2alpha and HIF-3alpha expressions increased during both intermittent and chronic hypoxia.
• Vascular endothelial growth factor, endothelin-1, and tyrosine hydroxylase showed varying expressions between the intermittent and chronic hypoxia groups.
• The differential regulation of HIF-alpha subtypes may explain the different morphological and neurochemical responses of the carotid body to intermittent and chronic hypoxia.

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