In a new study published in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology, researchers examined how changes in metabolism during torpor are regulated in 13-lined ground squirrels (Ictidomys tridecemlineatus). During hibernation, these animals cycle between bouts of torpor (about 2 weeks each) when their metabolism is reduced by 95% and body temperature can drop to 5degC and short states of interbout euthermia when both temperature and metabolism rise to normal. By examining how the mitochondria switch between torpor and normal metabolism, the researchers discovered that key metabolic enzymes can change quickly as a result of changes in proteins after they are created as opposed to gene modifications that occur before proteins are made. The results of the study suggest that researchers may be able to manipulate these pathways one day to induce similar reductions in mitochondrial function to perhaps produce a state of synthetic torpor.
Mathers KE, Staples JF. Differential posttranslational modification of mitochondrial enzymes corresponds with metabolic suppression during hibernation. American Journal of Physiology – Regulatory, Integrative and Comparative Physiology. 317(2): R262-R269. https://doi.org/10.1152/ajpregu.00052.2019