The disposition of intravenous potassium in normal man: the role of insulin.
1. Potassium infusion causes an increase in immunoreactive insulin levels in dogs, but either a small (30%) or no increase in humans. Since insulin stimulates the uptake of K+ by cells, a regulatory role for K+-induced insulin release has been postulated. To study the role of insulin in regulating cellular K+ uptake, six fasting normal volunteer subjects underwent two K+ infusions on separate days. Both infusions delivered 0.6 mmol h-1 kg-1 for 3 h. In one subject glucose was simultaneously infused at 0.67 mmol h-1 kg-1 (a rate known to increase peripheral insulin levels by 40-100%); the other infusion contained no glucose. 2. Plasma insulin levels did not increase during the glucose-free infusions. During glucose-containing infusions, insulin levels were 40% higher than those during glucose-free infusions. Despite this, neither urinary potassium excretion nor the increment in plasma K+ concentration or the calculated cellular K+ uptake differed significantly during the 3 h of glucose-free and glucose-containing infusions respectively. 3. These data do not support the view that potassium-induced insulin secretion regulates cellular potassium uptake within the physiological range of plasma K+ concentration.
D001786:Blood Glucose / Q000378:metabolism; D005110:Extracellular Space / Q000378:metabolism; D005246:Feedback; D005947:Glucose / Q000494:pharmacology; D006706:Homeostasis; D006801:Humans; D007263:Infusions, Parenteral; D007328:Insulin / Q000097:blood / Q000502:physiology*; D008297:Male; D011188:Potassium / Q000008:administration & dosage / Q000097:blood* / Q000652:urine
D001786:Blood Glucose; D007328:Insulin; D005947:Glucose; D011188:Potassium