[Metabolic effects of acute experimental hypoxia and hypercapnia]

Hypoxia and the hypercapnia were produced in anesthetized dogs by artificial respiration with appropriate gas mixtures, and a study was conducted of the effects of these conditions on various metabolic parameters, viz. catecholamines, renin activity, lactate, pyruvate, cortisol, non-esterified free fatty acids (FFA), and ammonia, in the plasma of the arterial blood. Hypercapnia caused a distinct increase in catecholamine concentrations, renin activity and ammonia, and a decrease in lactate and pyruvate; cortisol and FFA levels were only slightly altered. Hypoxia increased lactate, pyruvate and--though only to a slight extent--FFA, cortisol and NH3. The changes induced by hypercapnia were chiefly attributable to activation of the sympathico-adrenal system; those induced by hypoxia were not.