Abstract
To evaluate the effects of glucocorticoids on the Na-K pump in human subjects, were evaluated the intracellular sodium and potassium, 42K influx across and the [3H]ouabain binding to cell membranes of intact human erythrocytes from a group of subjects taking glucocorticoids and a group of normal subjects. Intracellular sodium concentration was lower (7.2 +/- 0.4 vs. 10.9 +/- 0.2 mmol/liter cell water) and intracellular potassium concentration higher (149.8 +/- 1.5 vs. 137.2 +/- 1.2 mmol/liter cell water) in erythrocytes from steroid-treated patients. In spite of a significantly decrease intracellular sodium which normally diminishes ouabain-sensitive 42K influx, the ouabain-sensitive K influx was unchanged in erythrocytes from the steroid-treated group. Maximum [3H]ouabain binding was markedly higher in the steroid-treated group (835 +/- 44 vs. 449 +/- 11 sites/cell). There was close linear correlation between [3H]ouabain binding and inhibition of K pump, suggesting the specificity of ouabain binding to Na-K pump sites on the cell membrane. Association kinetics for ouabain were similar in the two groups despite the marked difference in the amount of [3H]ouabain binding. External potassium concentration required for half-maximum ouabain-sensitive K influx was identical in the two groups. Thus, the additional Na-K pump sites in the steroid-treated group were qualitatively similar to those in normals. These results suggest that administration of glucocorticoids leads to an increase in the number of Na-K pump sites. The increase in the number of Na-K pump sites may explain the low levels of intracellular sodium and higher cell potassium observed in steroid-treated subjects.
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Selected References
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- BERNSTEIN R. E. Alterations in metabolic energetics and cation transport during aging of red cells. J Clin Invest. 1959 Sep;38:1572–1586. doi: 10.1172/JCI103936. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Baker P. F., Willis J. S. Binding of the cardiac glycoside ouabain to intact cells. J Physiol. 1972 Jul;224(2):441–462. doi: 10.1113/jphysiol.1972.sp009904. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chapman R. G., Schaumburg L. Glycolysis and glycolytic enzyme activity of aging red cells in man. Changes in hexokinase, aldolase, glyceraldehyde-3-phosphate dehydrogenase, pyruvate kinase and glutamic-oxalacetic transaminase. Br J Haematol. 1967 Sep;13(5):665–678. doi: 10.1111/j.1365-2141.1967.tb08832.x. [DOI] [PubMed] [Google Scholar]
- Charney A. N., Kinsey M. D., Myers L., Gainnella R. A., Gots R. E. Na+-K+-activated adenosine triphosphatase and intestinal electrolyte transport. Effect of adrenal steroids. J Clin Invest. 1975 Sep;56(3):653–660. doi: 10.1172/JCI108135. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cole C. H., Maletz R. Changes in erythrocyte membrane ouabain-sensitive adenosine triphosphatase after renal transplantation. Clin Sci Mol Med. 1975 Mar;48(3):239–242. doi: 10.1042/cs0480239. [DOI] [PubMed] [Google Scholar]
- Cook J. S. Nonsolvent water in human erythrocytes. J Gen Physiol. 1967 May;50(5):1311–1325. doi: 10.1085/jgp.50.5.1311. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Erdmann E., Hasse W. Quantitative aspects of ouabain binding to human erythrocyte and cardiac membranes. J Physiol. 1975 Oct;251(3):671–682. doi: 10.1113/jphysiol.1975.sp011115. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Feldman D., Funder J. W., Edelman I. S. Subcellular mechanisms in the action of adrenal steroids. Am J Med. 1972 Nov;53(5):545–560. doi: 10.1016/0002-9343(72)90152-0. [DOI] [PubMed] [Google Scholar]
- Fisher K. A., Welt L. G., Hayslett J. P. Dissociation of Na-K-ATPase specific activity and net reabsorption of sodium. Am J Physiol. 1975 Jun;228(6):1745–1749. doi: 10.1152/ajplegacy.1975.228.6.1745. [DOI] [PubMed] [Google Scholar]
- Gall G., Usher P., Melby J. C., Klein R. Effects of aldosterone and cortisol on human erythrocyte Na efflux. J Clin Endocrinol Metab. 1971 Apr;32(4):555–561. doi: 10.1210/jcem-32-4-555. [DOI] [PubMed] [Google Scholar]
- Garrahan P. J., Garay R. P. A kinetic study of the Na pump in red cells: its relevance to the mechanism of active transport. Ann N Y Acad Sci. 1974;242(0):445–458. doi: 10.1111/j.1749-6632.1974.tb19108.x. [DOI] [PubMed] [Google Scholar]
- Glynn I. M., Karlish S. J. The sodium pump. Annu Rev Physiol. 1975;37:13–55. doi: 10.1146/annurev.ph.37.030175.000305. [DOI] [PubMed] [Google Scholar]
- Hendler E. D., Torretti J., Kupor L., Epstein F. H. Effects of adrenalectomy and hormone replacement on Na- K-ATPase in renal tissue. Am J Physiol. 1972 Mar;222(3):754–760. doi: 10.1152/ajplegacy.1972.222.3.754. [DOI] [PubMed] [Google Scholar]
- Joiner C. H., Lauf P. K. Modulation of ouabain binding and potassium pump fluxes by cellular sodium and potassium in human and sheep erythrocytes. J Physiol. 1978 Oct;283:177–196. doi: 10.1113/jphysiol.1978.sp012495. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Joiner C. H., Lauf P. K. Ouabain binding and potassium transport in young and old populations of human red cells. Membr Biochem. 1978;1(3-4):187–202. doi: 10.3109/09687687809063847. [DOI] [PubMed] [Google Scholar]
- Joiner C. H., Lauf P. K. The correlation between ouabain binding and potassium pump inhibition in human and sheep erythrocytes. J Physiol. 1978 Oct;283:155–175. doi: 10.1113/jphysiol.1978.sp012494. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Joiner C. H., Lauf P. K. The effect of anti-L on ouabain binding to sheep erythrocytes. J Membr Biol. 1975 Apr 23;21(1-2):99–112. doi: 10.1007/BF01941064. [DOI] [PubMed] [Google Scholar]
- Jorgensen P. L. Regulation of the (Na+ equals K+)-activated ATP hydrolyzing enzyme system in rat kidney. II. The effect of aldosterone on the activity in kidneys of adrenalectomized rats. Biochim Biophys Acta. 1969 Nov 18;192(2):326–334. [PubMed] [Google Scholar]
- Knight A. B., Welt L. G. Intracellular potassium. A determinant of the sodium-potassium pump rate. J Gen Physiol. 1974 Mar;63(3):351–373. doi: 10.1085/jgp.63.3.351. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Loes M. W., Singh S., Lock J. E., Mirkin B. L. Relation between plasma and red-cell electrolyte concentrations and digoxin levels in children. N Engl J Med. 1978 Sep 7;299(10):501–504. doi: 10.1056/NEJM197809072991001. [DOI] [PubMed] [Google Scholar]
- Sachs J. R. Sodium movements in the human red blood cell. J Gen Physiol. 1970 Sep;56(3):322–341. doi: 10.1085/jgp.56.3.322. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sachs J. R., Welt L. G. The concentration dependence of active potassium transport in the human red blood cell. J Clin Invest. 1967 Jan;46(1):65–76. doi: 10.1172/JCI105512. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Smith E. K., Samuel P. D. Abnormalities in the sodium pump of erythrocytes from patients with hyperthyroidism. Clin Sci. 1970 Jan;38(1):49–61. doi: 10.1042/cs0380049. [DOI] [PubMed] [Google Scholar]
- WELT L. G., SACHS J. R., MCMANUS T. J. AN ION TRANSPORT DEFECT IN ERYTHROCYTES FROM UREMIC PATIENTS. Trans Assoc Am Physicians. 1964;77:169–181. [PubMed] [Google Scholar]
- Wiley J. S. Co-ordinated increase of sodium leak and sodium pump in hereditary spherocytosis. Br J Haematol. 1972 May;22(5):529–542. doi: 10.1111/j.1365-2141.1972.tb05700.x. [DOI] [PubMed] [Google Scholar]
- Wiley J. S., Ellory J. C., Shuman M. A., Shaller C. C., Cooper R. A. Characteristics of the membrane defect in the hereditary stomatocytosis syndrome. Blood. 1975 Sep;46(3):337–356. [PubMed] [Google Scholar]
- Wiley J. S., Shaller C. C. Selective loss of calcium permeability on maturation of reticulocytes. J Clin Invest. 1977 Jun;59(6):1113–1119. doi: 10.1172/JCI108735. [DOI] [PMC free article] [PubMed] [Google Scholar]
