Abstract
It is recognized that brain oxygen deprivation results in increased glycolysis and lactate accumulation. Moreover, glucose metabolism is altered during starvation or diet, resulting in increased plasma ketones (acetoacetate + β-hydroxybutyrate; BHB). We investigated glucose and lactate adaptation to hypoxia in concurrence with diet-induced ketosis. Male Wistar rats were fed standard (STD), ketogenic (high fat; KG), or carbohydrate-rich (low fat; CHO) diets for 3 wks and then exposed to hypobaric (0.5 ATM) or normobaric atmosphere for 3 wks while on their diets. Lactate, ketones, and glucose concentrations were measured in plasma (mM) and brain tissue (mmol/g). Plasma and tissue ketone levels were elevated up to 12-fold in the KG fed groups compared with other groups (STD and CHO), with the hypoxic KG group reaching the highest levels (2.6 ± 1.3 mM and 0.3 ± 0.1 mmol/g; mean ± SD). Tissue lactate levels in the hypoxic ketotic rats (4.7 ± 1.3 mM) were comparable with normoxic STD (5.0 ± 0.7 mM) and significantly lower (ANOVA P<.05) than the hypoxic STD rats (6.1 ± 1.0 mM). These data indicate that adaptation to hypoxia did not interfere with ketosis, and that ketosis during hypoxia may lower lactate levels in brain, suggesting decreased glycolysis or increased glucose disposal.
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Puchowicz, M.A. et al. (2005). Adaptation to Chronic Hypoxia During Diet-Induced Ketosis. In: Okunieff, P., Williams, J., Chen, Y. (eds) Oxygen Transport to Tissue XXVI. Advances in Experimental Medicine and Biology, vol 566. Springer, Boston, MA. https://doi.org/10.1007/0-387-26206-7_8
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DOI: https://doi.org/10.1007/0-387-26206-7_8
Publisher Name: Springer, Boston, MA
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