Metabolic interactions of dichloroacetate and insulin in experimental diabetic ketoacidosis

Abstract

1. The infusion of sodium dichloroacetate into rats with severe diabetic ketoacidosis over 4h caused a 2mM decrease in blood glucose, and small falls in blood lactate and pyruvate concentrations. Similar findings had been reported in normal rats (Blackshear et al., 1974). In contrast there was a marked decrease in blood ketone-body concentration in the diabetic ketoacidotic rats after dichloroacetate treatment. 2. The infusion of insulin alone rapidly decreased blood glucose and ketone bodies, but caused an increase in blood lactate and pyruvate. 3. Dichloroacetate did not affect the response to insulin of blood glucose and ketone bodies, but abolished the increase of lactate and pyruvate seen after insulin infusion. 4. Neither insulin nor dichloroacetate stimulated glucose disappearance after functional hepatectomy, but both agents decreased the accumulation in blood of lactate, pyruvate and alanine. 5. Dichloroacetate inhibited 3-hydroxybutyrate uptake by the extra-splachnic tissues; insulin reversed this effect. Ketone-body production must have decreased, as hepatic ketone-body content was unchanged by dicholoracetate yet blood concentrations decreased. 6. It was concluded that: (a) dichloroacetate had qualitatively similar effects on glucose metabolism in severely ketotic rats to those observed in non-diabetic starved animals; (b) insulin and dichloroacetate both separately and together, decreased the net release of lactate, pyruvate and alanine from the extra-splachnic tissues, possibly through a similar mechanism; (c) insulin reversed the inhibition of 3-hydroxybutyrate uptake caused by dichloroacetate; (d) dichloroacetate inhibited ketone-body production in severe ketoacidosis.