The regulation of plasma ketone body concentration by counterregulatory hormones in man.

Previous studies have attributed norepinephrine's ketogenic activity to its ability to mobilize peripheral fat stores. This study was designed to determine whether norepinephrine has ketogenic activity independent of its lipolytic effect in diabetic man. Six insulin-dependent diabetic subjects were infused with pathophysiologic concentrations of norepinephrine (0.08 microgram./kg./min.). As a control for norepinephrine's lipolytic effect, a separate heparin-induced free fatty acid generation study was performed on each subject. The results demonstrate, for the first time in man, that norepinephrine has ketogenic activity independent of its lipolytic effect. Furthermore, physiologic elevations of norepinephrine concentration were also demonstrated to increase plasma glucagon concentration. Our data are consistent with the possibility that the rise in concentration of glucagon may have a participated in the catecholamine-augmented ketogenesis.