Natural hypometabolism during hibernation and daily torpor in mammals.

摘要: Daily torpor and hibernation are the most powerful measures of endotherms to reduce their energy expenditure. During entrance into these torpid states metabolic rate is suppressed a fraction euthermic metabolism, paralleled by reductions in ventilation heart rate. Body temperature gradually decreases towards level ambient temperature. In deep body as well controlled at hypothermic hypometabolic level. Torpid terminated an arousal where spontaneously returns normal levels again established burst heat production. recent years some cellular mechanisms which contribute hypometabolism have been disclosed. Transcription, translation, protein synthesis largely suppressed. Cell proliferation highly proliferating epithelia like intestine suspended. ATP production from glucose reduced lipids serve major substrate for remaining requirements. All changes rapidly reverted normometabolism during arousal. Hibernation daily found small mammals inhabiting temperate tropical climates. It indicates that this behaviour not primarily aimed cold defense, instead points general role hypometabolism, measure cope with timely limited or seasonal bottleneck supply.