Carotid chemoreceptor denervation does not impair hypoxia-induced thermal downregulation but vitiates recovery from a hypothermic and hypometabolic state in mice

Abstract

Induction of hypothermia and consequent hypometabolism by pharmacological downmodulation of the internal thermostat could be protective in various medical situations such as ischemia/reperfusion. Systemic hypoxia is a trigger of thermostat downregulation in some mammals, which is sensed though carotid chemoreceptors (carotid bodies, CBs). Using non-invasive thermographic imaging in mice, we demonstrated that surgical bilateral CB denervation does not hamper hypoxia-induced hypothermia. However, the recovery from a protective and reversible hypothermic state after restoration to normoxic conditions was impaired in CB-resected mice versus control animals. Therefore, the carotid chemoreceptors play an important role in the central regulation of hypoxia-driven hypothermia in mice, but only in the rewarming phase.