Biological time-related changes in tolerance of male rats to hypoxia--I. Survival rate and carbohydrate metabolism.
Investigations were carried out on male Wistar rats, synchronized in standard conditions to a light-dark regiment (LD 12:12 with L from 0600 to 1800). Rats exposed to hypoxia equivalent to 10,500m at a clock-hour of 1000 had a survival time twice as long as that of animals exposed at 2200. Data from this study indicate the ability to mobilize energy stores through the conversion of liver glycogen to glucose along with circadian differences in hormonal response (e.g. corticosterone and insulin) contributes to the tolerance to hypoxia being greater during diurnal rest than nocturnal activity in rats.
D000204:Activity Cycles; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D001923:Brain Chemistry; D050260:Carbohydrate Metabolism; D002940:Circadian Rhythm; D003345:Corticosterone / Q000097:blood; D004734:Energy Metabolism; D000860:Hypoxia / Q000378:metabolism / Q000503:physiopathology*; D007328:Insulin / Q000097:blood; D007773:Lactates / Q000032:analysis; D019344:Lactic Acid; D008099:Liver / Q000032:analysis; D008112:Liver Glycogen / Q000032:analysis; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains / Q000502:physiology; D012146:Rest
D001786:Blood Glucose; D007328:Insulin; D007773:Lactates; D008112:Liver Glycogen; D019344:Lactic Acid; D003345:Corticosterone