Correction of hypokalemia corrects the abnormalities in erythrocyte sodium transport in Bartter's syndrome.

Korff, JM; Siebens, A W; Gill, Jr Jr

doi:10.1172/jci111590

Cited by 21 publications

(6 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…None of the observations thus far explain the molecular cause of the transport defect. The intriguing hypothesis that the primary abnormality is a generalized increase in cellular sodium permeability with a resultant stimulation of Na/K-ATPase and consequent distal tu bule potassium wasting is as yet untested [32], Of note, other cell membranes appear to share the renal tubular defect [29][30][31].…”

Section: Discussionmentioning

confidence: 99%

Variant of Bartter’s Syndrome with a Distal Tubular rather than Loop of Henle Defect

Puschett¹,

Greenberg²,

Mitro³

et al. 1988

Nephron

View full text Add to dashboard Cite

A 19-year-old normotensive patient had all of the clinical features of Bartter’s syndrome: hypokalemia, elevated renin and aldosterone levels and increased excretion of prostaglandin E. In contrast to the patients described by Bartter, the patient had a normal capacity to form solute-free water, suggesting intact loop of Henle function. Baseline potassium and chloride excretion rates were higher than those observed in 5 normal subjects, but the response to intravenous chlorothiazide, a drug which acts in the early distal convolute tubule, was abnormal. While chloride excretion rose by only 61% in this patient, it increased sixfold in the normal subjects. Sodium excretion quadrupled in the controls but less than doubled in this patient. Roughly equivalent increments in potassium excretion occurred in normals and controls, suggesting that the patient’s distal potassium-secretory mechanism was intact. Review of the literature indicates that whether the site of the abnormal renal tubular potassium (chloride) leak is the proximal tubule, the loop of Henle or the distal convoluted tubule, patients may achieve features indistinguishable from those previously reported as characteristic for Bartter’s syndrome. If loop of Henle malfunction is required to diagnose classical Bartter’s syndrome, then our patient (and several reported elsewhere) has a variant form.

show abstract

Section: Discussionmentioning

confidence: 99%

Variant of Bartter’s Syndrome with a Distal Tubular rather than Loop of Henle Defect

Puschett¹,

Greenberg²,

Mitro³

et al. 1988

Nephron

View full text Add to dashboard Cite

show abstract

“…The selectivity of the cation channel is some twofold higher for K + than for Na + [21]. In view of the intracellular Na + and K + concentrations of approximately 10-20 mM [16,26,37,40] and 140 mM [37], respectively, and the extracellular concentrations of 145 mM and 5 mM, respectively, the equilibrium potential for the channel approaches some 18 mV, i.e. a value more negative than the actual cell membrane potential.…”

Section: Impact Of Cation Channels On Cell Volumementioning

confidence: 99%

Cation channels, cell volume and the death of an erythrocyte

Läng

Lang

Wieder

et al. 2003

Pfl�gers Archiv European Journal of Physiology

View full text Add to dashboard Cite

Similar to a variety of nucleated cells, human erythrocytes activate a non-selective cation channel upon osmotic cell shrinkage. Further stimuli of channel activation include oxidative stress, energy depletion and extracellular removal of Cl-. The channel is permeable to Ca2+ and opening of the channel increases cytosolic [Ca2+]. Intriguing evidence points to a role of this channel in the elimination of erythrocytes by apoptosis. Ca2+ entering through the cation channel stimulates a scramblase, leading to breakdown of cell membrane phosphatidylserine asymmetry, and stimulates Ca(2+)-sensitive K+ channels, thus leading to KCl loss and (further) cell shrinkage. The breakdown of phosphatidylserine asymmetry is evidenced by annexin binding, a typical feature of apoptotic cells. The effects of osmotic shock, oxidative stress and energy depletion on annexin binding are mimicked by the Ca2+ ionophore ionomycin (1 microM) and blunted in the nominal absence of extracellular Ca2+. Nevertheless, the residual annexin binding points to additional mechanisms involved in the triggering of the scramblase. The exposure of phosphatidylserine at the extracellular face of the cell membrane stimulates phagocytes to engulf the apoptotic erythrocytes. Thus, sustained activation of the cation channels eventually leads to clearance of affected erythrocytes from peripheral blood. Susceptibility to annexin binding is enhanced in several genetic disorders affecting erythrocyte function, such as thalassaemia, sickle-cell disease and glucose-6-phosphate dehydrogenase deficiency. The enhanced vulnerability presumably contributes to the shortened life span of the affected erythrocytes. Beyond their role in the limitation of erythrocyte survival, cation channels may contribute to the triggering of apoptosis in nucleated cells exposed to osmotic shock and/or oxidative stress.

show abstract

“…The exact transmembrane topology of these channels is not yet well understood, and it is especially unclear whether the region near the carboxy-terminal is formed by 4 or 5 transmembrane domains. ClC-Kb belongs to this family rects the intracellular cation abnormalities but has little effect on the membrane transport defect, while complete correction of hypokalemia apparently normalizes all parameters [96].…”

Section: ªClassicº Bartter Syndromementioning

confidence: 99%

Bartter and related syndromes: the puzzle is almost solved

Rodríguez‐Soriano

1998

Pediatric Nephrology

163

147

View full text Add to dashboard Cite

It is now evident that the term Bartter syndrome does not represent a unique entity but encompasses a variety of disorders of renal electrolyte transport. Application of molecular biology techniques has permitted a better understanding of these "Bartter-like syndromes," which at present can be divided into three different genetic and clinical entities. Neonatal Bartter syndrome is observed in newborn infants and characterized by polyhydramnios, premature delivery, life-threatening episodes of fever and dehydration during the early weeks of life, growth retardation, hypercalciuria, and early-onset nephrocalcinosis. Two molecular defects have been identified: either at the gene encoding the renal bumetanide-sensitive Na-K-2Cl cotransporter (NKCC2) or the gene encoding an ATP-sensitive inwardly rectifying K channel (ROMK). "Classic" Bartter syndrome is mostly observed during infancy and childhood and is characterized clinically by polyuria and growth retardation. Nephrocalcinosis is not present. Very recently, either deletions or mutations at the gene encoding a renal chloride channel (ClC-Kb) have been identified. Gitelman syndrome is observed in older children and adults presenting with intermittent episodes of muscle weakness and tetany, hypokalemia, and hypomagnesemia. Mutations at the gene encoding the thiazide-sensitive Na-Cl cotransporter have been identified in the majority of patients studied. Obviously the validity of this classification must be confirmed in the near future when all mutations have been described and genotypic-phenotypic correlations are better defined.

show abstract

Correction of hypokalemia corrects the abnormalities in erythrocyte sodium transport in Bartter's syndrome.

Cited by 21 publications

References 23 publications

Variant of Bartter’s Syndrome with a Distal Tubular rather than Loop of Henle Defect

Variant of Bartter’s Syndrome with a Distal Tubular rather than Loop of Henle Defect

Cation channels, cell volume and the death of an erythrocyte

Bartter and related syndromes: the puzzle is almost solved

Contact Info

Product

Resources

About