The growth rate of Sarcoma 180 and of a mammary adenocarcinoma in potassium deficient mice did not significantly differ from that in pair-fed control mice. The po tassium concentration of these tumors in potassium-deficient mice was the same as in the control mice, although the potassium concentration of muscle and plasma was only half of that in the controls. The in vivo equilibration of K@ in...

The experiments described below were designed to study the effects of changes in extracellular potassium concentration [K]o on the basal tone, the contractile response to Z-norepinephrjne and the tissue concentration of potassium [K] t of helical rabbit aorta strips. The results suggest that in this preparation when [K]o is increased, the change in resting length due to the potassium change is ...

The potassium content of muscle fibers depends, in part, upon the potassium concentration of the external medium (Fenn and Cobb, 1934). In tissues intact in the body, it has been shown that sodium enters the fibers as potassium leaves, either because of low potassium in the blood (Heppel, 1939, 1940) or because of activity or fatigue (Fenn, 1938). Such findings suggest that the normal accumulat...

The potassium content of muscle fibers depends, in part, upon the potassium concentration of the external medium (Fenn and Cobb, 1934). In tissues intact in the body, it has been shown that sodium enters the fibers as potassium leaves, either because of low potassium in the blood (Heppel, 1939, 1940) or because of activity or fatigue (Fenn, 1938). Such findings suggest that the normal accumulat...

The constant association of a fall in concentration of serum potassium with attacks of muscular weakness, plus the relief of the weakness by the administration of potassium salts, have clearly indicated that familial periodic paralysis involves a defect in potassium metabolism. The nature of this is not completely understood. Following the observation that the concentration of potassium in seru...

Automatic neuron firing is an important and interesting research subject in neuroelectrophysiology. Through the original Hodgkin-Huxley model, we investigate its codimension 1 bifurcations along maximum conductance of the sodium channel, maximum conductance of potassium channel, and extracellular potassium concentration. We find that increasing maximum conductance of sodium channel, or decreasi...

Cells of the red marine alga, Porphyra perforata, accumulate potassium and exclude sodium, chloride, and calcium. Various metabolic inhibitors including dinitrophenol, anoxia, and p-chloromercuribenzoate partially abolish the cells' ability to retain potassium and exclude sodium. Iodoacetate induces potassium loss only in the dark; reduced sulfur compounds offer protection against the effects o...

Cell motility was measured by the degree of the fluctuation of the light intensity which pass through optical microscope (X 150) observing systems. The photodiode was mounted on the eye-piece lense and its output was fed into the operational amplifier and finally connected to memory oscilloscope. The degree of cell motility was determined by the average amplitude of the intensity fluctuation ca...

Hyperkalaemia is defined as serum potassium concentration greater than 5.5 mmol/l. Its prevalence in the general population is unknown, but it is thought to occur in 1-10% of patients admitted to hospital.1 The rate of morbidity and mortality associated with hyperkalaemia has risen greatly with the use of drugs that target the renin-angiotensin system, and since publication 10 years ago of a ra...