Inhibition of glycolysis in the denervated dog heart

We measured glucose metabolism in five dogs before and 3 weeks after cardiac denervation; after this time myocardial norepinephrine is depleted. The discharge by the myocardium, of 14CO2 from infused 14C-D-glucose (U), decreased following denervation (P = 0.05). The ratio of 14CO2 to total CO2 production, which measured the proportion of glucose to total substrate oxidized, also decreased following denervation (P = 0.05). The inhibition of glucose oxidation by denervation was not due to an increase in arterial lactate concentration. There was an associated increase in myocardial content of fructose-6-phosphate in an additional seven dogs (P < 0.01). We postulate that myocardial tissue norepinephrine is one of the controllers of the activity of phosphofructokinase.