In 2017, it was discovered that naked mole rats (Heterocephalus glaber) could survive up to 18 minutes in an anoxic (0% oxygen) environment without any permanent damage to the organism. The normal body temperature of naked mole rats is 30°C, making them poikilothermic animals that are able to operate at a range of body temperatures and to alter its body temperature based upon the environment. Even if the animals are warmed to 37°C, they still survive 6 minutes in an anoxic environment, which is still more than 5 minutes longer than the survival of other rodents like mice. You are already familiar with the H. glaber hemoglobin, but as usual, this does not fully explain the naked mole rat ability to survive anoxia.
Blood glucose concentrations during anoxia were found to be similar in mice and mole rats, but during normoxic (normal oxygen levels) conditions, naked mole rate had a blood glucose concentration of 3.49mM while mice had 6.66mM, making them appear hypoglycemic compared to other rodents and mammals.
Brain slices from mice and the naked mole rat were incubated with 13C6-D-Fructose in hypoxic conditions. The fate of the 13C was determined in the metabolites listed in Table 1.
Table 1: Metabolic flux of fructose metabolites in the hypoxic brain
Metabolite
Mouse
Naked Mole Rat
Glyceraldehyde-3-phosphate
500
3000
Pyruvate
140
260
Lactate
20000
75000
Citrate
700
1500
Succinate
60
70
All values are in pmol 13C in 50mg tissue measured 30 minutes after addition of 13C6-D-Fructose.
What does this indicate about the metabolic fate of fructose and sucrose in the naked mole rat as compared to the mouse?
In 2017, it was discovered that naked mole rats (Heterocephalus glaber) could survive up to 18 minutes in an anoxic (0% oxygen) environment without any permanent damage to the organism. The normal body temperature of naked mole rats is 30°C, making them poikilothermic animals that are able to operate at a range of body temperatures and to alter its body temperature based upon the environment. Even if the animals are warmed to 37°C, they still survive 6 minutes in an anoxic environment, which is still more than 5 minutes longer than the survival of other rodents like mice. You are already familiar with the H. glaber hemoglobin, but as usual, this does not fully explain the naked mole rat ability to survive anoxia.
Blood glucose concentrations during anoxia were found to be similar in mice and mole rats, but during normoxic (normal oxygen levels) conditions, naked mole rate had a blood glucose concentration of 3.49mM while mice had 6.66mM, making them appear hypoglycemic compared to other rodents and mammals.
Brain slices from mice and the naked mole rat were incubated with 13C6-D-Fructose in hypoxic conditions. The fate of the 13C was determined in the metabolites listed in Table 1.
Table 1: Metabolic flux of fructose metabolites in the hypoxic brain
| Metabolite | Mouse | Naked Mole Rat |
| Glyceraldehyde-3-phosphate | 500 | 3000 |
| Pyruvate | 140 | 260 |
| Lactate | 20000 | 75000 |
| Citrate | 700 | 1500 |
| Succinate | 60 | 70 |
All values are in pmol 13C in 50mg tissue measured 30 minutes after addition of 13C6-D-Fructose.
What does this indicate about the metabolic fate of fructose and sucrose in the naked mole rat as compared to the mouse?
