Effect of potassium on human and rat liver glucose-6-phosphatase.

Potassium chloride concentrations of 100-150 mM were shown to inhibit (20-40%) human and rat liver microsomal glucose-6-phosphatase when the substrate was reduced to physiological concentration. When the enzyme was solubilized by treatment of microsomes with A12O3 the inhibition could be observed at greater substrate concentrations. Since potassium deprivation is associated with hyperglycemia in both animals and man, these observations may have physiological significance.