January 24, 2022 1:10 pm

Shaved ratopines hide the secret of survival without oxygen

Small underground rodents, with wrinkled skin and almost hairless, the slashed ratpines O naked mole rats (Heterocephalus glaber) are as tough as they are strange. Not only do they tolerate pain, they overcome cancer, they live for about 30 years, but they are also able to remain without oxygen up to 18 minutes.

Shaved ratopines are heterothermic, that is, they are thermoregulated, but their internal temperature can also vary according to needs

Matthew Pamenter

Now researchers from the University of Ottawa (Canada) have discovered how this mammal can save energy in case of hypoxia – reducing its metabolic rate by up to 85% – and survive in low oxygen conditions. The results are published in the journal Nature Communications.

For scientists it was a mystery to understand how these small rodents, which until now were considered to be cold blood and whose body temperature was believed to vary depending on the environment, thermoregulation or produce heat, an activity that demands a lot of energy, while experiencing the oxygen deficiency, in which case saving energy is essential for survival.

“We wanted to know how they compensate for thermoregulation and energy saving in hypoxia. We found that they turn off thermogenesis without chills (in mitochondrial brown adipose tissue) very quickly through a novel mechanism ”, he explains Matthew Pamenter, associate professor in the department of Biology at the Canadian university and director of the Pamenter laboratory.

The data thus shows that they not only actively generate heat, but can modulate this generation very quickly in the event of hypoxia. “Therefore, they are heterothermic, that is to say, they are thermoregulated, but their internal temperature can also vary according to the needs ”, emphasizes the researcher.

top rats temperature

A: Naked mole rat in normoxia. Bright yellow / red / orange colors indicate that the region between the shoulder blades is the hottest part of the animal. This is where most of the brown adipose tissue is located and therefore the main source of heat generated by chill-free thermogenesis. Image B: The same animal in hypoxia. The animal is darker in color and very close to the background color, indicating that its body temperature has basically dropped to room temperature (or very slightly above). / Matthew Pamenter

A unique mechanism

The procedure by which these African mammals tolerate hypoxia -related to many human-related pathologies, such as stroke o go chronic lung disorders– sheds light on how nature has solved the problem of oxygen starvation tolerance, the study says. To live without him the key is hypometabolism, or reducing energy use.

The procedure by which these African mammals tolerate hypoxia sheds light on how nature has solved the problem of tolerance to lack of oxygen

The scientists found a mechanism that consists of the rapid elimination of the uncoupling protein (UCP1) of the cells of the brown adipose tissue intrascapular. “Rats can do it in one hour of exposure to moderate hypoxia, while in other small rodents the reduction of UCP1 takes more than three days. This is an important step in understanding how naked mole rats can save energy in hypoxia and survive in a hypoxic environment, ”says Pamenter.

On the other hand, after traveling to South Africa, with the support of a scholarship National Geographic Explorers, to collect tissues from other species of mole rats used in this study, in collaboration with Nigel BennetA researcher at the University of Pretoria in South Africa, the team found that a similar rapid change in UCP1 occurs with exposure to hypoxia in these animals as well.

However, it does not occur in a solitary species. “This suggests that this response may be driven by the social structure of the colony in small rodents (naked mole rats are an eusocial species, like bees and ants) ”, adds the scientist.


Hang Cheng,  et al. “Naked mole-rat brown fat thermogenesis is diminished during hypoxia through a rapid decrease in UCP1” Nature Communications

Source: SINC

Rights: Creative Commons.


Comments (0)

Leave a Reply

Your email address will not be published. Required fields are marked *