呼吸还是进食？高原小鼠的生存权衡

In highland mice, the responses to low oxygen and toxins compete for a shared molecular regulator M. Denise Dearing Life at high altitude presents many challenges to mammals. Solar radiation is high, food and water are scarce, temperatures are persistently low, and decreased oxygen severely limits aerobic life. For example, at 5000 m above sea level, the partial pressure of oxygen (a measure of the availability of oxygen in air) is just half that at sea level. A mammal from sea level transported to this altitude would need to breathe at a much higher rate to achieve similar blood concentrations of oxygen. However, this would result in excessive loss of carbon dioxide (CO2) and make body fluids overly basic (alkalosis). …