EFFECT OF POTASSIUM INTAKE ON THE FINAL STEPS OF ALDOSTERONE BIOSYNTHESIS IN THE RAT

1973 ◽  
Vol 73 (1) ◽  
pp. 80-90 ◽  
Author(s):  
Jürg Müller ◽  
Klaus Baumann
Keyword(s):  
Potassium Concentration ◽  
Plasma Potassium ◽  
Zona Glomerulosa ◽  
Total Body Potassium ◽  
Deficient Diet ◽  
Potassium Intake ◽  
Aldosterone Production ◽  
Potassium Restriction ◽  
Total Body ◽  
Sodium And Potassium

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.

scholarly journals Fluctuations in plasma potassium in patients on dialysis

2019 ◽  
Vol 34 (Supplement_3) ◽  
pp. iii19-iii25
Author(s):  
Csaba P Kovesdy
Keyword(s):  
Potassium Concentration ◽  
Plasma Potassium ◽  
Total Body Potassium ◽  
Potassium Balance ◽  
Increased Risk ◽  
Total Body ◽  
Stage Renal Disease ◽  
End Stage ◽  
The Impact

Abstract Plasma potassium concentration is maintained in a narrow range to avoid deleterious electrophysiologic consequences of both abnormally low and high levels. This is achieved by redundant physiologic mechanisms, with the kidneys playing a central role in maintaining both short-term plasma potassium stability and long-term total body potassium balance. In patients with end-stage renal disease, the lack of kidney function reduces the body’s ability to maintain normal physiologic potassium balance. Routine thrice-weekly dialysis therapy achieves long-term total body potassium mass balance, but the intermittent nature of dialytic therapy can result in wide fluctuations in plasma potassium concentration and consequently contribute to an increased risk of arrhythmogenicity. Various dialytic and nondialytic interventions can reduce the magnitude of these fluctuations, but the impact of such interventions on clinical outcomes remains unclear.

Relation of Arterial Pressure with Body Sodium, Body Potassium and Plasma Potassium in Essential Hypertension

1982 ◽  
Vol 63 (3) ◽  
pp. 257-270 ◽  
Author(s):  
C. Beretta-Piccoli ◽  
D. L. Davies ◽  
K. Boddy ◽  
J. J. Brown ◽  
A. M. M. Cumming ◽  
...  
Keyword(s):  
Essential Hypertension ◽  
Arterial Pressure ◽  
Potassium Concentration ◽  
Plasma Potassium ◽  
Normal Subjects ◽  
Total Body Potassium ◽  
Hypertensive Patients ◽  
Body Sodium ◽  
Low Renin Hypertension ◽  
Total Body

1. Exchangeable sodium (NaE), plasma electrolytes and arterial pressure were measured in 121 normal subjects and 91 patients with untreated essential hypertension (diastolic >100 mmHg), 21 of whom had low-renin hypertension. Plasma concentrations of renin, angiotensin II and aldosterone were measured in all hypertensive patients, total body sodium, total body potassium and exchangeable potassium (KE) in some patients. 2. Mean NaE was not different in normal and hypertensive subjects provided the two groups were matched for leanness index. In the subgroup of young hypertensive patients aged 35 years or less mean NaE was below normal. NaE was not related to arterial pressure in normal subjects but in hypertensive patients there were positive and significant correlations of arterial pressure with NaE and with total body sodium. 3. NaE and total body sodium increased with age in hypertensive but not in normal subjects. Partial regression analysis suggested that the correlation of NaE with arterial pressure was not explained by an influence of age. 4. Mean NaE was not increased and mean KE was not decreased in patients with low-renin hypertension. 5. Plasma potassium concentration, KE and total body potassium correlated inversely and significantly with blood pressure in hypertensive patients. These correlations were more marked in young than in old patients. 6. Multiple regression analysis showed that the combination of NaE and plasma potassium concentration ‘explained’ more of the variation of systolic blood pressure in hypertensive patients than it did in normal subjects. Plasma potassium concentration ‘explained’ more of the variation in young hypertensives and NaE ‘explained’ more in older patients. 7. Our findings suggest that changes of plasma and body potassium are important in the earlier stages of essential hypertension and that changes of body sodium become important later.

Effects of aldosterone on potassium distribution

1982 ◽  
Vol 243 (5) ◽  
pp. R526-R530
Author(s):  
D. B. Young ◽  
T. E. Jackson
Keyword(s):  
Potassium Concentration ◽  
Correlation Coefficients ◽  
Plasma Potassium ◽  
The Body ◽  
Electrolyte Balance ◽  
Potassium Intake ◽  
Independent Variable ◽  
Total Body ◽  
Total Potassium

To assess the effects of long-term changes in aldosterone on potassium distribution within the body, two groups of experiments were conducted. In the first, seven normal dogs received continuous infusion of aldosterone at a high physiological rate, 250 micrograms/day. Total exchangeable potassium (Ke) and plasma potassium concentration (KP) were measured before and 4 and 6 days after aldosterone infusion. KP fell by 20% while Ke decreased by 8% after 6 days of infusion; the ratio between extracellular and total body potassium had been altered by the aldosterone infusion. In the second study, 10 adrenalectomized dogs received aldosterone infusion first at 50 micrograms/day, then at 250 micrograms/day. While on each level of aldosterone infusion, three levels of potassium intake were given by iv infusion. When the animals were in electrolyte balance at each level of aldosterone and potassium (after at least 7 days on each level of infusion), Ke (expressed as meq/kg) and KP were measured. The two variables were plotted against each other, Ke being the independent variable. Data taken while the dogs received 50 micrograms/day aldosterone were described by the equation, KP = 0.100Ke + 0.055, while those obtained at 250 micrograms/day were fitted by the equation, KP = 0.057Ke + 1.30. The correlation coefficients for the two were 0.778 and 0.760, respectively. The regressions were significantly different at a level of P less than 0.02. Data from the two groups of experiments are consistent with the hypothesis that aldosterone alters the distribution of potassium between the intra- and extracellular spaces, a greater portion of total potassium being intracellular at higher levels of aldosterone.

Relation of Arterial Pressure with Exchangeable and Total Body Sodium and with Plasma Exchangeable and Total Body Potassium in Essential Hypertension

1981 ◽  
Vol 61 (s7) ◽  
pp. 81s-84s ◽  
Author(s):  
C. Beretta-Piccoli ◽  
D. L. Davies ◽  
K. Boddy ◽  
J. J. Brown ◽  
A. M. M. Cumming ◽  
...  
Keyword(s):  
Arterial Pressure ◽  
Potassium Concentration ◽  
Young Patients ◽  
Plasma Potassium ◽  
Normal Subjects ◽  
Exchangeable Sodium ◽  
Total Body Potassium ◽  
Hypertensive Patients ◽  
Body Sodium ◽  
Total Body

1. Arterial pressure, plasma electrolytes and exchangeable sodium were measured in 91 patients with essential hypertension and in 121 normal control subjects. Total body sodium, exchangeable potassium and total body potassium were also measured in some of the hypertensive patients. 2. Mean plasma sodium concentration was slightly but significantly lower in the hypertensive patients as a group, but mean values for other electrolyte measurements were close to normal or predicted normal. 3. Exchangeable sodium was not related to arterial pressure in normal subjects but in hypertensive patients exchangeable sodium correlated significantly with systolic and diastolic pressures. These correlations were significant with two methods of expressing exchangeable sodium, in the whole group of patients, in men and in older patients. Exchangeable sodium was not significantly related to arterial pressure in young patients. 4. Total body sodium also correlated significantly with systolic and diastolic pressures in hypertensive patients. 5. Exchangeable sodium was significantly related to age in hypertensive patients but not in normal subjects. Mean exchangeable sodium was significantly lower than normal in young patients. 6. Plasma potassium concentration was not related to arterial pressure in normal subjects but in essential hypertensive patients plasma potassium concentration, exchangeable potassium and total body potassium correlated negatively with systolic and diastolic pressures. These correlations were also significant in young, but not in old patients.

Effects of sodium intake on steady-state potassium excretion

1984 ◽  
Vol 246 (6) ◽  
pp. F772-F778 ◽  
Author(s):  
D. B. Young ◽  
T. E. Jackson ◽  
U. Tipayamontri ◽  
R. C. Scott
Keyword(s):  
Steady State ◽  
Potassium Concentration ◽  
Sodium Intake ◽  
Plasma Potassium ◽  
Potassium Excretion ◽  
Distal Nephron ◽  
Concentration Data ◽  
Potassium Intake ◽  
Independent Variable ◽  
The Relationship

The effects of changes in sodium intake on the steady-state relationship between plasma potassium concentration and potassium excretion were studied in 15 chronically adrenalectomized dogs. Throughout the experiments the dogs received aldosterone at a rate of 50 micrograms/day and methylprednisolone at 1 mg/day. The relationship between plasma potassium and steady-state potassium excretion was obtained by changing potassium intake from 10 to 30 to 100 meq/day, each level being maintained for 7-10 days. At the conclusion of each period at a given level of potassium intake, plasma potassium and excretion were measured and plotted, plasma potassium being the independent variable. Such a relationship was obtained while the dogs were on three different levels of sodium intake: 10, 100, and 200 meq/day. The curves from the data obtained at 100 and 200 meq/day sodium intake both were shifted to the left of the curve obtained at 10 meq/day (P less than 0.05), although the 100 and 200 meq/day curves were not different from each other. On the basis of these data one could predict that, at a plasma potassium concentration of 4.0 meq/liter, the animals would excrete potassium at a rate of 17 meq/day on a 10 meq/day sodium intake, 37 meq/day on a 100 meq/day sodium intake, and 47 meq/day on a 200 meq/day sodium intake. Urine flow and electrolyte concentration data are consistent with the hypothesis that the sodium intake effect on potassium excretion was mediated through increases in distal nephron flow rate and decreases in distal nephron potassium concentration.

Inhibition of aldosterone-induced antinatriuresis and kaliuresis by actinomycin D

1984 ◽  
Vol 246 (2) ◽  
pp. F201-F204 ◽  
Author(s):  
J. D. Horisberger ◽  
J. Diezi
Keyword(s):  
Urinary Excretion ◽  
Intravenous Infusion ◽  
Sodium Excretion ◽  
Actinomycin D ◽  
Potassium Concentration ◽  
Plasma Potassium ◽  
Potassium Excretion ◽  
Short Term ◽  
Sodium And Potassium ◽  
Term Response

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.

Na and K levels in blood and marrow cells of normal and phenylhydrazine-treated rabbits

1962 ◽  
Vol 203 (2) ◽  
pp. 283-285 ◽  
Author(s):  
James W. Archdeacon ◽  
Harold C. Rohrs
Keyword(s):  
Blood Cells ◽  
Bone Marrow Cells ◽  
Potassium Concentration ◽  
Plasma Potassium ◽  
Progressive Increase ◽  
Ionic Concentration ◽  
Normal Bone ◽  
Slight Rise ◽  
Sodium And Potassium ◽  
Marrow Cells

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.

THE EFFECT OF MUSCULAR EXERCISE ON PLASMA SODIUM AND POTASSIUM IN THE RAT

1958 ◽  
Vol 36 (3) ◽  
pp. 333-338 ◽  
Author(s):  
F. A. Sréter ◽  
Sydney M. Friedman
Keyword(s):  
Potassium Concentration ◽  
Plasma Potassium ◽  
Sodium Concentration ◽  
Plasma Sodium ◽  
Preliminary Training ◽  
Plasma Sodium Concentration ◽  
Rate Of Increase ◽  
Response To Exercise ◽  
Sodium And Potassium

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.

Interrelated effects of aldosterone and plasma potassium on potassium excretion

1983 ◽  
Vol 244 (1) ◽  
pp. F28-F34 ◽  
Author(s):  
D. B. Young ◽  
A. W. Paulsen
Keyword(s):  
Renal Function ◽  
Potassium Concentration ◽  
Plasma Potassium ◽  
Potassium Excretion ◽  
Normal Range ◽  
Potassium Intake ◽  
Group I ◽  
Urinary Potassium ◽  
The Relationship ◽  
Renal Potassium Excretion

The interacting effects of aldosterone and plasma potassium concentration on steady-state renal potassium excretion were studied in two groups of chronically adrenalectomized dogs. In group I (six dogs, 22.9 kg) aldosterone was infused intravenously at 20 micrograms/day while potassium intake was changed in steps of 7-10 days duration from 10 to 30 to 100 meq/day. At the completion of each step, plasma potassium concentration, urinary potassium excretion, and other variables that potentially may affect renal function were measured. In group II (six dogs, 22.2 kg) a similar protocol was followed except that aldosterone was infused at 250 micrograms/day and the potassium intake levels were 30, 100, and 200 meq/day. Plasma potassium concentration and excretion data for the 20 micrograms/day group were: 3.22 +/- 0.26 meq/liter and 5 +/- 1 meq/day, 4.35 +/- 0.08 meq/liter and 21 +/- 2 meq/day, and 5.88 meq/liter and 82 +/- 3 meq/day at the 10, 30, and 100 meq/day intake levels, respectively. For the 250 micrograms/day group the values were: 2.72 +/- 0.18 meq/liter and 28 +/- 7 meq/day, 4.16 +/- 0.14 meq/liter and 71 +/- 8 meq/day, and 4.40 +/- 0.14 meq/liter and 172 +/- 26 meq/day at the 30, 100, and 200 meq/day intake levels. Therefore, the increase in aldosterone infusion rate shifted the relationship between plasma potassium concentration and potassium excretion to the left so that at a given level of plasma potassium a greater amount of potassium was excreted. In the normal range of plasma potassium concentration (4.00-4.40 meq/liter) the increase in aldosterone levels resulted in a four- to eightfold increase in daily potassium excretion.

Total Body Potassium in Patients Receiving Chlorthalidone and Metoprolol for Hypertension

1983 ◽  
Vol 28 (2) ◽  
pp. 172-175 ◽  
Author(s):  
J. M. B. Gray ◽  
D. H. Lawson ◽  
K. Boddy ◽  
W. East
Keyword(s):  
Blood Cell ◽  
Plasma Potassium ◽  
Fixed Dose ◽  
Average Period ◽  
Total Body Potassium ◽  
Total Blood ◽  
Hypertensive Patients ◽  
Dose Combination ◽  
Β Blocker ◽  
Total Body

Measurements of potassium status were reviewed in 23 hypertensive patients receiving metoprolol either alone or in combination with chlorthalidone or chlorthalidone plus potassium over an average period of nine months. There was no statistically significant change in plasma potassium, total blood cell or total body groups developed hypokalaemia (serum potassium <3.0mmol/l) in the absence of significant falls in total blood cell or total body potassium. Thus the use of chlorthalidone plus potassium did not provide adequate prophylaxis against hypokalaemia even in metoprolol recipients. The study confirms that monitoring parameters of potassium handling is still necessary in β-blocker recipients who also receive diuretics alone or in a fixed-dose combination with potassium.

Sign in / Sign up

Export Citation Format

Share Document