Accumulation Of Potassium Ions Research Articles

Aspartic acid and the accumulation of potassium ions in cerebral tissue

Aspartic acid and the accumulation of potassium ions in cerebral tissue

Intracellular distribution of cations and protein in regenerating rat liver

The intracellular distribution of several cell constituents was studied at different periods after partial hepatectomy in the rat. The temporal pattern of cation and protein distribution can be divided into two phases: there is an initial phase in the first 24 hr posthepatectomy in which sodium and water increased in tissues concomitant with a decrease in potassium and protein. The levels of these several constituents subsequently approached values that were higher than in the control at 1 and 2 days posthepatectomy and were generally maintained at these values throughout the assay period. The reasons for the accumulation of higher than normal levels of both potassium and sodium are as yet uninterpreted; the higher than control potassium-to-sodium ratios generally observed in the intracellular compartments are due to the relative greater accumulation of potassium ions over sodium ions during this period. Comparing the intracellular compartments, the greatest alterations of constituents in the early phases of liver regeneration were observed in the soluble portion.

Some observations on the effect of D-glutamate on the glucose metabolism and the accumulation of potassium ions in brain cortex slices.

Some observations on the effect of D-glutamate on the glucose metabolism and the accumulation of potassium ions in brain cortex slices.

Linkage of Physico-Chemical Processes in Biological Systems

IN a previous communication1 Prof. F. G. Donnan—to whose kindness I am much indebted—has developed further an idea arising out of work in this laboratory2, concerning the cellular accumulation of potassium ions in association with an intracellular chemical reaction. In this process an external diffusible anion, after passing through the membrane into the cell, is converted into an indiffusible anion or anion complex (using the term ‘indiffusible’ with respect to the membrane). The case chosen by Prof. Donnan was the simplest, in order to illustrate the principles involved. An important biological limitation of this simplest system would be that equilibrium can occur in this case only with a pressure difference if the potassium is accumulated. On discussing this matter with Prof. Donnan, it seemed to us of interest to present the condition when this limitation disappears, and in terms of the symbols of his letter.

THE COMPOSITION OF FLUIDS AND SERA OF SOME MARINE ANIMALS AND OF THE SEA WATER IN WHICH THEY LIVE

1. The electrolyte composition, the pH, and freezing points of the fluids of several invertebrates and one primitive chordate are reported. 2. Fluids of the worms, echinoderms, and the clam Venus were isotonic with sea water; fluids of the Arthropoda were hypertonic to sea water. 3. The pH of all fluids was below that of sea water. In the Arthropoda and Myxine less individual variation in pH appeared than in the echinoderms and worms. 4. Ratios of ionic concentrations in the fluid to those in the sea water indicated (1) uniform distribution of ions between the internal and external media for the echinoderms and Venus, (2) differential distribution of potassium and magnesium in the worms; (3) differential distribution of sulfate, magnesium, potassium, and calcium in the Arthropoda; and (4) differential distribution of calcium, magnesium, and sulfate in Myxine. 5. The unequal distribution of ions implies the expenditure of energy against a concentration gradient across the absorbing or excreting membranes, a capacity frequently overlooked in the invertebrates. 6. The sera of the Arthropoda from diluted sea water showed higher concentrations of sodium, potassium, calcium, and chloride ions relative to the respective concentrations in the external medium than in normal sea water, and also showed different orders for those ions. 7. The increase in osmotic pressure of the sera of the animals moving into brackish water is caused by unequal accumulation of sodium, potassium, calcium, and chloride ions. Sulfate and magnesium ionic ratios do not change.