potassium-bicarbonate and Hyponatremia

In experiments on nonlinear rats, the renal functions were investigated at aqueous diuresis induced by intragastric administration of sodium potassium, potassium hydrocarbonate (20 mM/kg), and potassium succinate (10 mM/kg). We have found that the load by potassium raised glomerular filtration rate and sharply increased excretion of not only K+ but also Na+ and Cl- with urine, that led to hyponatremia and hypochloremia following hyperkalemia. In addition, the intracellular concentration of K+ increased more than extracellular one, especially after administrating KHCO3 and potassium succinate. It promoted potassium efflux from cells by concentration gradient, hyperpolarization of cellular membrane and vascular smooth muscle relaxation. Thus, these data explain renal mechanisms of a known protective effect of potassium at essential hypertension.

Topics: Animals; Bicarbonates; Cell Membrane; Chlorides; Diuresis; Glomerular Filtration Rate; Hyperkalemia; Hypertension, Renovascular; Hyponatremia; Kidney; Muscle Contraction; Muscle, Smooth, Vascular; Potassium; Potassium Compounds; Rats; Sodium; Succinic Acid