Effect of fasting on hypoxia tolerance of mice in relation to oxygen consumption and heart rate.
Mice more than 8 weeks old were fasted for 1 or 2 d and challenged by severe acute hypoxia. The hypoxia survival times (ST) were compared to the body weight, oxygen consumption (VO2), or heart rate (HR) of each animal. The duration of fasting was found to be important to determine ST. VO2 or HR were negatively correlated with ST, whether mice were fasted or not. The regression line (InST on HR) in the fed (control) group did not significantly differ from that of 2-d fasted groups, but those of fed and 1-d fasted groups differed. These results suggested that, in fasting for 2 d, the reduction in energy consumption was a major determining factor of hypoxia survival; in 1-d fasting, other factors might operate to determine the tolerance.
D000818:Animals; D001835:Body Weight; D004734:Energy Metabolism; D005215:Fasting; D006339:Heart Rate; D000860:Hypoxia / Q000503:physiopathology*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D010100:Oxygen / Q000097:blood*
D010100:Oxygen