scholarly journals CATION EXCHANGE BETWEEN CELLS AND PLASMA OF MAMMALIAN BLOOD

1951 ◽  
Vol 34 (4) ◽  
pp. 411-429 ◽  
Author(s):  
C. W. Sheppard ◽  
W. R. Martin ◽  
Gertrude Beyl

Sodium and potassium exchange has been studied in the blood of the sheep, dog, cow, and man. The potassium exchange rate in human cells is practically unaltered by increasing the plasma potassium concentration approximately threefold. Comparing the results in different species the exchange rate for potassium shows a rough correlation with the intracellular amount of the element. Expressed in per cent of the cellular content sodium tends to exchange more rapidly than potassium. In three instances the specific activity curves deviate from the simple exponential behavior of a two compartment system. In the exchange of potassium in canine blood the deviation is caused by the presence of a rapidly exchanging fraction in the buffy coat cells. Such an effect does not account for the inhomogeneity of sodium exchange in human blood.

1950 ◽  
Vol 33 (6) ◽  
pp. 703-722 ◽  
Author(s):  
C. W. Sheppard ◽  
W. R. Martin

The exchange of potassium between cells and plasma of heparinized human blood has been studied in vitro using the radioactive isotope K42. The changes in cell and plasma specific activity are characteristic of a simple two-compartment system. The mean of seven determinations of the exchange rate at 38°C. is 1.8 per cent of the cellular potassium per hour. The results indicate that at 38°C. the rate is relatively insensitive to oxygenation or reduction of the hemoglobin, and to 1200 r of gamma radiation. With varying temperature the rate follows pseudo first order kinetics with a Q10 of 2.35. Below 15°C. the rate of loss of potassium exceeds the rate of uptake.


1966 ◽  
Vol 49 (6) ◽  
pp. 1111-1124 ◽  
Author(s):  
H. BURR STEINBACH

Intact living frogs (Rana pipiens) were partially immersed in dilute salt solution labeled with K42 or Na24 or, alternatively, injected with Ringer’s fluid containing the appropriate isotope and then partially immersed in unlabeled dilute salt. Before isotopic equilibrium, the animals were sacrificed and specific activities of K42 and Na24 were determined for medium, skin, plasma, and other tissues. With Na24, entering from the medium or escaping to the medium, specific activities of the skin approach that of the plasma. For K42, entering from the medium, the specific activity exceeds that of the plasma. The results are interpreted as indicating that the exchange rate for Na is greater plasma to skin than medium to skin, with the reverse situation for K. Values are given for average Na, K, and Cl contents of the various organ systems.


1984 ◽  
Vol 246 (2) ◽  
pp. F201-F204 ◽  
Author(s):  
J. D. Horisberger ◽  
J. Diezi

The effects of actinomycin D on short-term response to aldosterone on sodium and potassium urinary excretion were investigated in adrenalectomized glucocorticoid-substituted anesthetized rats. Aldosterone alone (1 microgram/kg followed by sustained intravenous infusion of 1 microgram X kg-1 X h-1) entailed a simultaneous antinatriuretic and kaliuretic effect after a latent period of 30-60 min. Actinomycin D (300 micrograms/kg) administered intravenously 30 min before aldosterone inhibited both the aldosterone-induced kaliuresis and antinatriuresis and the concomitant changes in plasma potassium concentration. The administration of actinomycin D alone enhanced sodium excretion in the first hour and then induced kaliuresis. These results favor the hypothesis that mineralocorticoid effects of aldosterone on sodium and potassium excretion are closely linked and may be dependent on the same mechanisms.


1962 ◽  
Vol 203 (2) ◽  
pp. 283-285 ◽  
Author(s):  
James W. Archdeacon ◽  
Harold C. Rohrs

Sodium and potassium contents of marrow cells, blood cells, and plasma were measured in normal rabbits and rabbits injected subcutaneously with phenylhydrazine to determine if small quantities of this chemical affected the ability of the blood and marrow cells to maintain their normal levels of these ions. There was a decrease in potassium content of red blood cells within 24 hr after administration of the compound, followed subsequently by a slight rise in plasma potassium. Apparently any effect was closely related to the time of blood sampling after the last injection, recovery occurring within several days if injections were not repeated at frequent intervals. The sodium and potassium analyses of normal bone marrow cells revealed differences in ionic concentration dissimilar to normal blood cells, the average sodium concentrations being higher and potassium concentrations lower in the former cells. Separation of marrow cells into three groups by prolonged centrifugation demonstrated a progressive increase in sodium and a decrease in potassium concentration from the lower to the upper stratum, possibly indicating a greater degree of ionic pumping in the more dense cells.


1958 ◽  
Vol 36 (3) ◽  
pp. 333-338 ◽  
Author(s):  
F. A. Sréter ◽  
Sydney M. Friedman

After running a distance of 100 meters in 7 minutes, untrained rats showed a rise in plasma potassium and a fall in plasma sodium as measured in tail vein samples. These changes are in accord with in vitro observations of the effects of exercise on isolated muscle preparations and similarly are taken to indicate a gain of sodium and a loss of potassium by the exercised muscles in the whole animal. Within 10 minutes of completion of the exercise, plasma sodium concentration was restored to normal while potassium was restored within 20 minutes. Exercise was accompanied by a fall in haematocrit, which remained low for up to 40 minutes. A period of 2 months of preliminary training modified the response to exercise. In these trained animals, a fall in sodium concentration occurred as before but the rise in potassium concentration was less in degree and the haematocrit did not change. It is suggested that the rate of increase of plasma potassium is an index of muscle efficiency while the height of plasma potassium is correlated with the fatigue limit of exercise.


1965 ◽  
Vol 209 (6) ◽  
pp. 1219-1226 ◽  
Author(s):  
Helen Cserr

Potassium exchange between cerebrospinal fluid (CSF), plasma, and brain was investigated in anesthetized dogs and rats using the technique of ventriculocisternal perfusion. Transport via bulk secretion and absorption of CSF accounts for only 20% of total potassium exchange, unidirectional ionic fluxes across the ependyma for 80%. This large transependymal exchange is primarily between CSF and brain intracellular potassium pools, since two-thirds of the K42 outflux can be recovered from brain tissue. Conversely, much of transependymal influx comes from brain, as demonstrated by the low specific activity of influx relative to that of plasma following intravenous injection of K42. Potassium outflux is almost proportional to CSF [K+] in the range 0–10 mEq/liter but is independent of plasma [K+]. Perfusion with 10–5 m ouabain reduces transependymal K42 outflux to 25% of control; the residual outflux may be accounted for by passive processes. Results are discussed in terms of 1) regulation of CSF potassium concentration and 2) the relationship between CSF and brain extracellular fluid.


1950 ◽  
Vol 33 (6) ◽  
pp. 691-702 ◽  
Author(s):  
John W. Raker ◽  
Isaac M. Taylor ◽  
John M. Weller ◽  
A. Baird Hastings

1. The exchange of potassium by the human erythrocyte has been studied in vitro using radioactive potassium. 2. An incubation technique which maintains erythrocytes in an essentially normal state for over 48 hours was employed. 3. Exchange of radioactive potassium between the red cells and the extracellular fluid was regular and progressive, the specific activities of the intra- and extracellular fluids reaching equal values. This indicates that all the erythrocyte potassium is exchangeable and is exchanging at the same rate. 4. From these data, it was calculated that at 37°C., 1.6 per cent of the erythrocyte potassium exchanges per hour, corresponding to an exchange of 1.5 mM of potassium per liter of red cells per hour. The time required for the exchange of 50 per cent of the red cell potassium is calculated to be 43 hours. 5. The temperature coefficient (Q10) of the potassium exchange rate is 2.2. This is the same as the temperature coefficient of the rate of utilization of glucose by the human erythrocyte. 6. Varying the percentage of red cells, plasma potassium concentration, initial glucose level, and pH between 7.0 and 7.7 had no effect on the potassium exchange rate.


1973 ◽  
Vol 73 (1) ◽  
pp. 80-90 ◽  
Author(s):  
Jürg Müller ◽  
Klaus Baumann

ABSTRACT Capsular adrenals ("zona glomerulosa") of rats which had been kept on a sodium- and potassium-deficient diet and which were markedly hypokalaemic, converted tritiated corticosterone to 18-hydroxycorticosterone and aldosterone, and tritiated cortexolone to cortisol at the same respective rates as the capsular adrenals of sodium- and potassium-replete animals. Aldosterone production from endogenous precursors was elevated under basal conditions of incubation, but not under stimulation by added serotonin. Corticosterone and deoxycorticosterone outputs were normal during incubation with or without serotonin. Capsular adrenals of rats which had been kept first on a potassium-deficient diet for two weeks and then on a sodium- and potassium-deficient diet for two weeks converted 18 times more tritiated corticosterone to 18-hydroxycorticosterone and aldosterone and produced 5 times more aldosterone from endogenous precursors than the tissue of rats which had been kept on the potassium-deficient diet for the whole period, although the serum potassium was similarly low in both groups. These results indicate that under simple potassium restriction as well as under combined sodium and potassium restriction, neither the plasma potassium concentration nor the total body potassium is the only regulator of the activity of the enzymes involved in the final steps of aldosterone biosynthesis.


1958 ◽  
Vol 196 (1) ◽  
pp. 141-144 ◽  
Author(s):  
Mary Jane Tompkins ◽  
Edward Eckman ◽  
Leonard Share

A study was made of the extrarenal action of the adrenal cortex on sodium and potassium metabolism in the rat. There was a reduction in the plasma potassium concentration 24 hours after the administration of desoxycorticosterone, 2 mg/rat, in the adrenalectomized-nephrectomized rat. Treatment with hydrocortisone, 5 mg rat, resulted in the opposite effect. Corticosterone and 2-methyl-9α-fluorohydrocortisone were without effect. In another series of experiments, adrenalectomy resulted in an elevation in the plasma potassium concentration in nephrectomized-eviscerated rats. This change could be detected as early as two hours after operation. The intravenous administration of large doses of desoxycorticosterone, hydrocortisone, corticosterone and aldosterone were without effect. It is suggested that there is a movement of potassium into the extracellular fluid in the absence of the secretions of the adrenal gland.


1958 ◽  
Vol 36 (1) ◽  
pp. 333-338
Author(s):  
F. A. Sréter ◽  
Sydney M. Friedman

After running a distance of 100 meters in 7 minutes, untrained rats showed a rise in plasma potassium and a fall in plasma sodium as measured in tail vein samples. These changes are in accord with in vitro observations of the effects of exercise on isolated muscle preparations and similarly are taken to indicate a gain of sodium and a loss of potassium by the exercised muscles in the whole animal. Within 10 minutes of completion of the exercise, plasma sodium concentration was restored to normal while potassium was restored within 20 minutes. Exercise was accompanied by a fall in haematocrit, which remained low for up to 40 minutes. A period of 2 months of preliminary training modified the response to exercise. In these trained animals, a fall in sodium concentration occurred as before but the rise in potassium concentration was less in degree and the haematocrit did not change. It is suggested that the rate of increase of plasma potassium is an index of muscle efficiency while the height of plasma potassium is correlated with the fatigue limit of exercise.


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