Hypobaric hypoxia affects endogenous levels of α-keto acids in murine heart ventricles

α-Keto acids have recently been identified as potent regulators of cellular adaptations to hypoxia. Their actual intracellular concentrations under such conditions are unknown. Here, we determined concentrations of α-ketobutyrate, α-ketoglutarate, α-ketoisocaproate, α-ketoisovalerate, α-keto-β-methylvalerate, phenylpyruvate, and pyruvate by a recently developed ultra-sensitive fluorescence HPLC method in ventricular myocardium of mice exposed to hypobaric hypoxia for up to 3 weeks. We observed characteristic alterations of cardiac α-keto acid concentrations that are specific for individual α-keto acids, show significant side differences (right versus left ventricles), and are suited to trigger some of the cardiac metabolic and structural adaptations to chronic hypoxia.