The peripheral vascular reactivity of potassium-deficient rats

Peripheral vascular reactivity was studied in the potassium-deficient and control rats by measuring the degree of blood pressure response to intravenously injected pressor substances. The pressor response consistently was less in the potassium-deficient rats. The significance of these results with regard to the hypotensive action of potassium deprivation is discussed.

Effect of potassium administration on peripheral vascular reactivity and blood pressure of the potassium-deficient rat

One hour after administration of potassium chloride to potassium-deficient rats, the depressed peripheral vascular response to pressor substances was significantly elevated. Administration of potassium chloride to potassium-deficient rats also returned to higher levels the lowered blood pressure of previously normotensive, as well as hypertensive rats. It appears that the depressor effect of potassium deprivation is due to the loss of peripheral vascular reactivity, both of which are rapidly restored by potassium administration specifically.

Severe acidosis and hyperpotassemia treated with sodium bicarbonate infusion

Four uremic patients with severe acidosis, hyperpotassemia, and electrocardiographic signs of toxicity were treated with intravenous sodium bicarbonate. Serial determinations showed a fall in plasma potassium, a rise in blood pH, and regression of the electrocardiogram toward normal. The mechanisms responsible for these changes are discussed.

Relationship of potassium and calcium to hypothermic ventricular fibrillation

Pentobarbital-anesthetized dogs, cooled in ice water to terminus, were found to have a 96% incidence of ventricular fibrillation. Plasma potassium levels were uniformly depressed at low body temperatures. Treatment with Intravenous potassium chloride, 150– 250 mg/kg, reduced the frequency of fibrillation to 57%. Administration of EDTA (ethylene diamine tetracetic acid), 75 mg/kg in divided doses, lowered serum calcium levels but affected the incidence of fibrillation only slightly. Combined therapy with potassium chloride and EDTA reduced the incidence of ventricular fibrillation to 50%. These results are interpreted as indicating that ionic imbalance observed with hypothermia produces a marked arrhythmic tendency and that proper alteration of plasma potassium levels reduces the danger of fibrillation.

Submitted on July 28, 1958