Potassium, glucose, insulin interrelationships during adrenaline infusion in normotensive and hypertensive humans.

1. Significant increases in arterial noradrenaline (NA) of similar magnitude were seen in normotensive (NT) and hypertensive humans (HT) during adrenaline (ADR) infusion. 2. Significant falls in plasma potassium (K+) were observed in both NT and HT during ADR infusion, even at rates equivalent to minor stress. Levels achieved were significantly lower in HT than in NT. 3. Plasma glucose increased significantly in HT at all ADR infusion rates but only at higher rates of infusion in NT. 4. Basal insulin levels were significantly higher in NT than in HT. After cessation of infusion, insulin increased three-fold in HT and two-fold in NT. 5. Infusion of ADR to produce levels seen during mild to moderate stress resulted in significant increases in plasma NA, falls in plasma K+ and increases in plasma glucose. The expected large insulin response to rising glucose was not seen until after ADR was ceased, confirming the inhibitory effect of ADR on glucose stimulated insulin release.