Improved 02 Transport and Utilization Capacity Following Intermittent Hypobaric Hypdxia in Rats
Numerous studies have shown that exposure to hypobaric hypoxia induces altered respiration as well as circulatory activities. It has been suggested that acclimatization to high altitude leads to increased capillary density1, red blood cell (RBC) counts and Hemoglobin (Hb) concentration2,3, which may play a beneficial role in maintaining energy production of the muscles with low Po2. Previous studies4 have indicated that elevation of respiratory enzyme activity occurs in some muscles with a high oxidative capacity. Although many studies have reported changes of skeletal muscle metabolism from sea level5 to hypobaric hypoxia, there are few studies that address the opposite process, i.e. from hypobaric hypoxia to sea level. Furthermore, respiratory alkalosis is initially induced by exposure to hypoxia, while the 02 dissociation curve is shifted to the right due to an increased level of 2,3-diphosphoglycerate (DPG) in RBC resulting from the hypoxemia and alkalosis6. This right shift of the 02 dissociation curve is assumed to facilitate a better 02 unloading in venous blood at a given Po2.
KeywordsPhenol Carbohydrate Lactate Citrate Respiration
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