Effects of time and duration of exposure to 12% O2 and prior food deprivation on hypoxic hypophagia of rats.
A low cost, gas-dilution type, high-altitude simulator was developed and found to be a useful model for studying the effect of acute hypoxic exposure on food consumption in the rat. A distinct advantage of this system is that it provides access to the animals without disturbance to the gaseous atmosphere. The onset of hypoxic hypophagia was shown to occur within the first 3 h following abrupt ascent to a simulated altitude of 4419.6 m (14,500 ft). The magnitude of the anorexic effect was uniform throughout the first day of exposure to 12% O2; likewise, food consumption rapidly recovered following return to a sea level atmosphere. It was concluded that the hypophagic effect of hypoxia is not absolute and that the severity of the hypophagia can be reduced by prior food deprivation. However, the degree of attenuation of the hypophagic response was not directly related to the length of the deprivation period. Food deprivation may sufficiently enhance metabolic-induced food demand signals to partially override the inhibitory effect of hypoxia on feeding behavior. Alternatively, metabolic perturbations associated with the food-deprived state may, in some undefined manner, minimize the severity of acute hypoxic stress.
D000532:Altitude Sickness / Q000097:blood*; D000818:Animals; D004435:Eating; D005508:Food Deprivation; D000860:Hypoxia / Q000097:blood*; D008297:Male; D010100:Oxygen / Q000097:blood*; D051381:Rats; D011919:Rats, Inbred Strains
D010100:Oxygen