Résumé : Sodium β-hydroxybutyrate was infused for 1.5 h in 8 normal subjects, at a constant rate of 5 mmoles/ kg/h. Equimolar amounts of sodium chloride were infused in 5 control subjects. - The induced hyperketonaemia provoked the following changes in peripheral blood: a fall in glycaemia (15 mg/100 ml) and in plasma NEFA concentration (50%) without concomitant modifications of insulin concentrations. These results indicate that the glucose and NEFA changes observed are not mediated by a pancreatic stimulation. © 1968 Springer-Verlag.