Anoxia Tolerance to Oxygen Necessity: Paradigm Shift in the Physiology of Survival of Apneic Deep Hypothermia in Neonatal Rodents

摘要: Neonatal small rodents stop breathing at body temperatures of 0–6oC, yet they often tolerate such hypothermia for several hours and recover spontaneously when rewarmed. The prevailing paradigm deep-hypothermia tolerance half a century has been that the heart stops beating; oxygen uptake delivery from environment stop; tissues are tolerant anoxia; this anoxia is key to survival. I here report does not beating in neonates survive hypothermia, even species earlier reported undergo cardiac arrest. Furthermore, as was 1955 but ignored, consume steadily low rates while apneic, consumption essential Thus, old must be succeeded by new one: Although may become hypoxic benefit hypoxia during apneic deep taken up across lungs; circulatory system likely transports oxygen; certain vital require influx if neonate survive.