Ion flux and Na+,K+-ATPase activity of erythrocytes and leucocytes in thyroid disease

1987 ◽  
Vol 72 (2) ◽  
pp. 171-179 ◽  
Author(s):  
F. A. Khan ◽  
D. N. Baron

1. In hyperthyroidism, erythrocytes show decreased Na+,K+-ATPase activity, decreased [3H]ouabain binding capacity (an index of the number of sodium pumps) and decreased active sodium and potassium flux rates, with a high intracellular sodium concentration. 2. As erythrocytes are non-nucleated and atypical cells, we have studied electrolyte status in thyroid disease using mixed leucocytes as well; the results obtained differed from those in erythrocytes. 3. When compared with findings in healthy subjects, leucocyte Na+,K+-ATPase activity, [3H]-oubain binding capacity, total and active rubidium (used instead of potassium) influx were all significantly increased in untreated hyperthyroidism and decreased in untreated hypothyroidism. 4. In hyperthyroidism, there was also a decrease in plasma potassium, an increase in sodium efflux rate and efflux rate constant, but no significant changes in cell sodium and potassium concentrations. All these changes returned to normal in successfully treated patients. There was a significant correlation between these abnormalities of electrolyte status and thyroid disease status (as serum thyroid stimulating hormone and free thyroxine).

1983 ◽  
Vol 64 (2) ◽  
pp. 177-182 ◽  
Author(s):  
E. Jill Rubython ◽  
D. B. Morgan

1. The sodium content, the ouabain-sensitive sodium efflux and efflux rate constant and the ouabain-binding capacity were measured in the erythrocytes of 53 patients with hypokalaemia and in 37 healthy controls. The sodium content alone was measured in a further 57 patients with hypokalaemia. 2. In the patients with hypokalaemia there was an increase in the average sodium content of the erythrocytes, which was entirely due to a reduction in the ouabain-sensitive efflux rate constant. 3. The ratio of the ouabain-sensitive efflux rate constant to the number of sodium pumps was decreased in the patients with hypokalaemia, and was directly related to the plasma potassium. 4. Many patients with moderate hypokalaemia had normal erythrocyte sodium and potassium contents and normal ouabain-sensitive efflux rate constant. These patients had an increased number of sodium pumps, which compensated for the inhibitory effect of hypokalaemia on each sodium pump. 5. This increase in the number of sodium pumps was common even in patients who had probably had hypokalaemia for less than 2 weeks. This finding suggests that there are latent sodium pumps within the circulating erythrocytes.


1962 ◽  
Vol 40 (1) ◽  
pp. 113-122 ◽  
Author(s):  
G. S. Kanter

The handling of sodium and potassium by the renal tubules at various levels of hypothermia was studied. Fourteen dogs were anesthetized with 30 mg/kg sodium pentobarbital. After suitable control clearance measurements, the rectal temperature was lowered progressively by ice-packing to about 25 °C while renal clearances were continuously measured. Artificial respiration was not used. No change in plasma sodium was detected but plasma potassium fell significantly from a control value of 4.1 ± 0.09 meq/1. at 38 °C to 3.4 ± 0.12 meq/1. at 25 °C. Urine sodium concentration fell during exposure to cold while potassium concentration increased slightly. In spite of the marked fall in glomerular nitration rate (69.0 ± 3.1 ml/minute control to 17.0 ± 3.6 ml/minute at 25 °C) the final urine flow at 25 °C was slightly greater than that of control. The clearance ratios (in percentage) increased significantly, reflecting the marked decrease in tubular reabsorption: water, 0.49 ± 0.05 at 38 °C to 2.02 ± 0.25 at 25 °C; sodium, 0.47 ± 0.12 to 1.13 ± 0.27; potassium, 18.0 ± 2.6 to 54.0 ± 12.0. The difference in clearance ratio alterations is a reflection of the dissimilar effect of hypothermia on particular renal regulations.


1973 ◽  
Vol 21 (4) ◽  
pp. 515 ◽  
Author(s):  
MR Hughes ◽  
JG Blackman

This is the first report of salt gland secretion in cranes (Gruidae). The sodium and potassium concentrations of the plasma, tears, salt gland secretion, and urine of the brolga were determined. Tear sodium was equal to plasma sodium; tear plasma was four times as concentrated as plasma potassium. These values were normal for tears. The salt gland secretion sodium concentration (about 300 m-equivll) was lower than that reported for other NaC1-injected birds. This may be due to the diet, small gland size, or to insufficient stress. The salt gland secretion to plasma ratios were the same for sodium and potassium. This is unusual. The urine had a lower sodium concentration than the plasma.


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.


1962 ◽  
Vol 40 (1) ◽  
pp. 113-122 ◽  
Author(s):  
G. S. Kanter

The handling of sodium and potassium by the renal tubules at various levels of hypothermia was studied. Fourteen dogs were anesthetized with 30 mg/kg sodium pentobarbital. After suitable control clearance measurements, the rectal temperature was lowered progressively by ice-packing to about 25 °C while renal clearances were continuously measured. Artificial respiration was not used. No change in plasma sodium was detected but plasma potassium fell significantly from a control value of 4.1 ± 0.09 meq/1. at 38 °C to 3.4 ± 0.12 meq/1. at 25 °C. Urine sodium concentration fell during exposure to cold while potassium concentration increased slightly. In spite of the marked fall in glomerular nitration rate (69.0 ± 3.1 ml/minute control to 17.0 ± 3.6 ml/minute at 25 °C) the final urine flow at 25 °C was slightly greater than that of control. The clearance ratios (in percentage) increased significantly, reflecting the marked decrease in tubular reabsorption: water, 0.49 ± 0.05 at 38 °C to 2.02 ± 0.25 at 25 °C; sodium, 0.47 ± 0.12 to 1.13 ± 0.27; potassium, 18.0 ± 2.6 to 54.0 ± 12.0. The difference in clearance ratio alterations is a reflection of the dissimilar effect of hypothermia on particular renal regulations.


1973 ◽  
Vol 44 (5) ◽  
pp. 439-445 ◽  
Author(s):  
P. J. Hilton ◽  
J. Patrick

1. Sodium and potassium efflux and influx rates were studied in normal human leucocytes in an artificial extracellular fluid using radioactive isotopes. 2. The rate constant for sodium efflux was 4.2 h−1 corresponding to a sodium efflux rate of 487 mmol kg cell dry weight−1 h−1. Approximately three-quarters of this flux was ouabain sensitive. 3. Potassium influx was 346 mmol kg cell dry weight−1 h−1. Approximately two-thirds of the potassium influx was ouabain insensitive.


1977 ◽  
Vol 6 (4) ◽  
pp. 659-663 ◽  
Author(s):  
G. J. Naylor ◽  
D. A. T. Dick ◽  
E. G. Dick ◽  
E. P. Worrall ◽  
M. Peet ◽  
...  

SynopsisErythrocyte sodium and potassium concentrations, erythrocyte membrane ATPase (Na–K specific and non-specific) and the rate of potassium influx into erythrocytes (ouabainsensitive and insensitive) were estimated in a group of female patients suffering from mania and repeated on about two thirds of them when they had recovered. With recovery there was a statistically significant increase in the erythrocyte ouabain-sensitive potassium influx. The other parameters showed no significant overall change with recovery but the initial severity correlated significantly and negatively with the change in erythrocyte Na–K ATPase with recovery. The changes that occurred in the erythrocyte sodium concentration and Na–K ATPase activity were not random since they correlated significantly with changes in the active potassium influx.


1996 ◽  
Vol 270 (2) ◽  
pp. C465-C473 ◽  
Author(s):  
N. A. Delamere ◽  
W. L. Dean ◽  
J. M. Stidam ◽  
A. E. Moseley

Active transport by Na(+)-K(+)-ATPase in the monolayer of lens epithelium is vital for the regulation of sodium and potassium levels within the mass of fiber cells that make up the bulk of the lens. In this study, experiments were conducted using porcine lenses to test whether Na(+)-K(+)-ATPase activity in the epithelium is altered when the permeability of lens cell plasma membranes is increased by the ionophore amphotericin B. After 24 h, sodium was significantly (P < 0.01) elevated in lenses exposed to 5 or 10 microM amphotericin B. Amphotericin B stimulated 86Rb uptake, probably through an increase of cytoplasmic sodium concentration due to increased inward sodium leak; the rate of ouabain-sensitive potassium (86Rb) uptake by intact lenses was significantly increased by amphotericin B at 5 microM (P < 0.05) and 10 microM (P < 0.01). After 24 h, the epithelium from lenses exposed to amphotericin B had an Na(+)-K(+)-ATPase activity that was more than twofold higher (P < 0.01) than the Na(+)-K(+)-ATPase activity in control lenses. By immunoblot, there was an increase in Na(+)-K(+)-ATPase catalytic (alpha) subunit immunoreactive polypeptide in the epithelium of lenses exposed to amphotericin B. The increase stemmed from a marked increase of Na(+)-K(+)-ATPase alpha 2-immunoreactive polypeptide but little change in the amount of alpha 1-immunoreactive protein. As judged by immunoblot experiments, the amount of Na(+)-K(+)-ATPase beta 1-immunoreactive polypeptide also appeared to be higher in the epithelium of amphotericin B-treated lenses compared with control lenses. In summary, these results suggest that in response to a permeability challenge with amphotericin B, the porcine lens epithelium is able to increase the activity of Na(+)-K(+)-ATPase. The same permeability challenge also appears to stimulate the biosynthesis of Na(+)-K(+)-ATPase catalytic subunit as well as glycoprotein subunit polypeptides.


1982 ◽  
Vol 242 (6) ◽  
pp. F664-F671 ◽  
Author(s):  
E. Natke ◽  
L. C. Stoner

The effects of varying endogenous aldosterone levels on the passive and active properties of the peritubular membrane were studied. Rabbits that were fed either a low Na+ (normal K+) diet or a high Na+, low K+ diet increased or decreased plasma aldosterone, respectively. Tubules were dissected, filled with oil, and incubated in 0 K+ medium to increase intracellular sodium. Cellular sodium and potassium content was measured by helium-glow photometry. The degree to which cells accumulate sodium and lose potassium is a function not only of time of exposure but also of diet. Tubules from animals on a low Na+ diet are about 6 times more permeable to sodium than those from animals fed a high Na+ diet. When tubules were loaded with sodium and returned to a normal (5 mM K+) bathing medium, net sodium efflux and potassium influx occurred. The rate of sodium efflux by cortical collecting tubules dissected from animals on the low Na+ diet was 2.3 times greater than the efflux rate of tubules from animals on the high Na+ diet. These data suggest that high levels of endogenous aldosterone enhance sodium transport measured in vitro across the peritubular membrane of cortical collecting tubule.


1989 ◽  
Vol 121 (1) ◽  
pp. 61-66 ◽  
Author(s):  
P. Jest ◽  
K. E. Pedersen ◽  
N. A. Klitgaard ◽  
N. Thomsen ◽  
E. Kjær ◽  
...  

Abstract. Bartter's syndrome is characterized by chronic hypokalaemia, activation of the renin-angiotensin system and normal blood pressure. To investigate whether a generalized disturbance of sodium-potassium pump function might be of pathogenetic importance, lymphocytic sodium-potassium homeostasis was examined in 5 patients suffering from Bartter's syndrome. Two of the patients were treated with potassium chloride supplementation, the others were without medical treatment when studied. All were severely hypokalemic (serum potassium 2.8 ± 0.24 mmol/l, mean ± sem). Lymphocyte sodium and potassium concentration (14.4 ± 0.37 and 94.4 ± 7.7 mmol/l, respectively), ouabain sensitive 22Na-efflux rate constant (2.68 ± 0.25 h −1), and absolute ouabain sensitive efflux rate (38.16 ± 4.2 mmol · I−1 · h−1) did not differ from matched controls. Ouabain binding capacity was 126900 ± 235000 sites/cell in the patients vs 50400 ± 17900 in controls (p <0.05). In conclusion, patients with Bartter's syndrome may have an intrinsic abnormal pump function, characterized by an increased pump density and a low cation turn-over rate per pump unit.


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