Plasma aldosterone concentration can increase in anephric man during hemodialysis despite the lack of kidneys to produce renin. Because the metabolic clearance rate of aldosterone does not change during hemodialysis, aldosterone secretion must increase in response to sodium depletion, volume depletion, or both. This study was designed to determine the relative influence of sodium and volume dep...

Blood samples were obtained from a radial artery cannula in a 60-yr-old man during coronary artery surgery. Serum potassium concentrations of 9.3, 8.4, and 7.4 mmol litre(-1) were obtained. A simultaneous venous blood sample gave a serum potassium concentration of 4.4 mmol litre(-1). The ECG was unchanged. After the arterial cannula was repositioned, subsequent blood samples gave expected range...

The urate concentration of the supernatant was greater after supersaturated solutions of sodium urate were incubated in a suspension of CM-Sephadex C-25 than in one of Sephadex G-25. The supernatant urate concentration was greater when the CM-Sephadex had been equilibrated with potassium than with sodium. The results are analogous with those obtained in studies of urate solubility in proteoglyc...

The posterior reticulated regions of the plasmodia of the slime mold, Physarum polycephalum, whose migration has been oriented by direct current (3.0 to 5.0 microa/mm(2) in the agar substrate), contain 30 per cent less potassium than the advancing non-reticulated region. The anterior regions have the same potassium concentration as that of the controls, approximately 32 meq/kg wet weight. Diffe...

Concern has been growing about the cardiac toxicity of antimalarial drugs. Artemisinin, a unique type of antimalarial drug originating from a Chinese medicinal plant, has minimal adverse effects, but it has been reported to inhibit delayed rectifier potassium current, a voltage-gated potassium current. However, no studies have been published concerning the effect of artemisinin on ligand-gated ...

Reported cochlear potential values of near 150 mV are often attributed to endolymph itself, although membrane potentials result from ion fluxes across the adjacent semipermeable membranes due to concentration gradients. Since any two fluids separated by a semipermeable membrane develop potential due to differences in solute concentrations, a proposed interpretation here is that positive potenti...

OBJECTIVE To describe profound hypokalemia in a comatose patient with diabetic ketoacidosis. METHODS We present a case report, review the mechanisms for the occurrence of hypokalemia in diabetic ketoacidosis, and discuss its management in the setting of hyperglycemia and hyperosmolality. RESULTS A 22-year-old woman with a history of type 1 diabetes mellitus was admitted in a comatose state....

Intact human erythrocytes can be readily loaded with calcium by incubation in hypersomotic media at alkaline pH. Erythrocyte calcium content increases from 15-20 to 120-150 nmol/g hemoglobin after incubation for 2 h at 20 degree C in a 400 mosmol/kg, pH 7.8 solution containing 100 mM sodium chloride, 90 mM tetramethylammonium chloride, 1 mM potassium chloride, and 10 mM calcium chloride. Calciu...

1. Fluid secretion by isolated salivary glands was stimulated by elevating the external potassium concentration. 2. The stimulatory effect of potassium was dependent on external calcium and was potentiated by a subthreshold dose of 5-hydroxytryptamine (5-HT). 3. During the action of 120 mM potassium there was a large calciumdependent decrease in transepithelial resistance similar to that produc...

Change of local cerebral blood flow in response to a single cortical spreading depression of Leão was studied in the brain. During a spreading depression, potassium briefly accumulates in the brain extracellular space. The cortical blood flow was normal during the maximal rate of increase of the extracellular potassium concentration. The blood flow doubled during the subsequent period of normal...