Related Experiment Videos
Working underground: respiratory adaptations in the blind mole rat
H R Widmer1, H Hoppeler, E Nevo
1Department of Anatomy, University of Bern, Switzerland.
Summary
Mole rats possess unique respiratory adaptations, including enhanced lung and muscle mitochondria, enabling high metabolic rates in low-oxygen environments. These adaptations improve oxygen diffusion but do not affect maximum oxygen uptake under normal conditions.
Area of Science:
- Comparative physiology
- Mammalian adaptation
- Hypoxia research
Background:
- Mole rats (Spalax ehrenbergi superspecies) thrive in hypoxic/hypercapnic subterranean environments.
- They exhibit unique metabolic responses, with high rates at high work and depressed rates at low work.
Purpose of the Study:
- To investigate respiratory system adaptations in mole rats compared to white rats.
- To understand how structural changes facilitate high metabolic rates under hypoxic conditions.
Main Methods:
- Comparative analysis of mole rats and white rats at the same body mass.
- Measurement of skeletal muscle mass, mitochondrial volume, and capillary density.
- Assessment of pulmonary diffusing capacity for oxygen (O2).
Main Results:
- Mole rats have less skeletal muscle mass but a higher fractional volume of muscle mitochondria.
- Increased capillary density in mole rat muscle reduces O2 diffusion distance.
- Mole rats exhibit greater structural pulmonary diffusing capacity for O2.
Conclusions:
- Structural adaptations in mole rat lungs and muscles enhance O2 diffusion, supporting high metabolic rates in hypoxia.
- These adaptations do not influence maximal oxygen uptake (V(O2max)) under normoxic conditions.