Erythrocyte Sodium Transport in Bartter's Syndrome

ABSTRACT. Erythrocyte sodium transport was evaluated by measurement of intracellular Na concentration (ICNa), ²²Na efflux rate constant (NaERC) and 3H-ouabain binding (BMax) (reflecting the number of Na/K ATPase pump sites) in 9 children with Bartter's syndrome compared to controls (children and adults) and children with various forms of salt wasting disease. There were no differences between control children and adults. In untreated Bartter's syndrome ICNa was significantly increased with NaERC and BMax significantly decreased compared to findings in controls and patients with other salt wasting disease. On prostaglandin synthetase inhibitor (Indomethacin) therapy, ICNa decreased but remained higher than in controls, NaERC increased to normal values but BMax remained low. These data support the view that there is a widespread defect in membrane electrolyte transport in Bartter's syndrome but suggest that the benefit of indomethacin therapy is not manifest via an effect on Na/K ATPase.     

Nephrocalcinosis in Bartter's syndrome

Nephrocalcinosis in Bartter's syndrome has been recognized since 1962, but has not previously been shown in an infant with the syndrome. Ultrasonography shows striking echogenicity of the renal pyramids which appears to be a specific finding in medullary nephrocalcinosis. We suspect nephrocalcinosis will be found in many infants with Bartter's syndrome if ultrasonography is used to examine their kidneys.     

Renal sonographic patterns in Bartter's syndrome

The renal sonographic findings in ten cases of Bartter's syndrome investigated at the King Khalid University Hospital, Riyadh, Saudi Arabia are described. There were various sonographic abnormalities other than those of hyperechoic pyramids as previously described. These were diffuse increased renal echogenicity and hyperechoic echogenicity in the kidneys with the exception of the pyramids. This condition can be suspected early if nephrocalcinosis is present in a child with a history of polyhydramnios and premature delivery.     

The role of prostaglandins in Bartter's syndrome

In two children with Bartter's syndrome, treatment with indomethacin halved the urinary excretion of prostaglandins E and F within 24 hours and subsequently maintained it within the normal range during follow-up for more than 5 years. Growth rate was improved and plasma renin and aldosterone and the urinary excretions of sodium and calcium fell to normal. Both children continued to lose excessive quantities of potassium in the urine. The results provide further evidence that over-production of prostaglandins is not the primary cause of Bartter's syndrome.     

Treatment of Bartter's syndrome with indomethacin

Two patients with Bartter's syndrome were treated with indomethacin (2 mg/kg/day). The administration of the drug resulted in weight gain; a decrease in the rate of urinary excretion of sodium and inorganic phosphate suggesting an increase in proximal tubular reabsorption; an increase in serum potassium concentration, with a transient decrease in the rate of urinary potassium excretion in one patient; and a decrease in plasma renin activity and in the rate of urinary aldosterone excretion. Since indomethacin has been shown to inhibit prostaglandin synthetase, these observations support the hypothesis that prostaglandin excess is a basic pathogenic mechanism in Bartter's syndrome.     

Association of Bartter's syndrome and empty sella

Bartter's syndrome is characterized by hypochloremia, hypokalemia, metabolic alkalosis associated with renal potassium leakage, and normal blood pressure despite increased plasma renin activity. Although association of empty sella with Gitelman syndrome has been reported, no association has been reported with Bartter's syndrome. Here we report a patient with Bartter's syndrome and empty sella. A 12 month-old male patient presented with a history of nausea, vomiting, abdominal distension, constipation, and edema in the lower extremities that had begun in the early postnatal period. The patient was born at 32 weeks gestation by operative delivery for polyhydramnios. Blood pressure was normal. Serum sodium, potassium, calcium, phosphate, chloride, albumin and alkaline phosphatase levels were 129 mEq/l, 2.5 mEq/l, 9 mg/dl, 3.8 mg/dl, 72 mg/dl, 4.2 g/dl and 1285 IU/l, respectively. Serum magnesium level was normal. Arterial blood gas levels revealed pH 7.55 (normal, 7.35-7.45), PCO2 33.6 mm/Hg (36-46), base excess +7.1 (+/- 2.3), and total CO2 33.6 mmol/l (23-27). Renin and aldosterone levels were elevated. Urine had pH 8.0 and specific gravity 1.010. Urinary calcium excretion was 22.8 kg/day (urine calcium/creatinine ratio 0.46). Urinary potassium and chloride levels were elevated. MRI of the brain was normal except for partially empty sella. We present the first pediatric patient with the association of Bartter's syndrome and empty sella.     

Bartter's syndrome and tubular functional disturbances]

A 5-year-old boy is presented who exhibited the classical symptoms of the syndrome described by BARTTER et al. in 1962: growth retardation, hypokalemic alkalosis, hyperplasia of the juxtaglomerular apparatus with normotensive hyperreninism-hyperaldosteronism, polydipsia with impaired renal concentration ability resistant to pitressin. In addition, the patient showed the typical proximal tubular defects of the Fanconi syndrome: hyperphosphaturia with hypophosphatemic ricktts, generalized hyperaminoaciduria, proteinuria and glucosuria. In the cases of Bartter's syndrome described to date, no uniform pathogenetic mechanism could be identified. Proximal tubular salt wasting generally is assumed to be the primary defect. The studies carried out in this case support this hypothesis and indicate that the complete clinical picture of Bartter's syndrome may occur within the framework of multiple proximal tubular defects.     

Bartter's syndrome: two case reports in childhood

OBJECTIVE: To report a syndrome that is uncommon in childhood and call pediatrician?attention to the tubular diseases - just like Bartters syndrome - in differential diagnosis of failure to thrive and other diseases that can be usually found in children.METHODS: Two patients are presented. The first, a 3 years and 2 months old boy who was submitted for investigation of a failure to thrive detected when he was 9 months old. The second patient, a 3 months old girl, was admitted to the Intensive Care Unit due to severe electrolyte disturbances. She was supposed to have a pyloric hypertrophic stenosis.RESULTS: Both patients had failure to thrive, hypocloremic alkalosis, hypokalemia, and hypercalciuria. The first had a positive obstetric history for polihydramnios that is frequently found in the neonatal form of this syndrome. Treatment was done by blood potassium correction, together with indometacin and spironolactone administration. These drugs where well tolerated by the patients who have improved their growth rhythm only a short time after electrolytic disturbances had been corrected.CONCLUSIONS: The Bartter's syndrome is a tubular disease that is unusual in childhood. It must be considered as a possible cause of failure to thrive. The neonatal form is rare and can produce severe hydro-electrolytic disturbances, increasing the difficulties for diagnosis. The treatment is well tolerated, even by small children, and must begin early to reduce the troubles to thrive.     

儿童Bartter综合征13例综合报告

目的探讨儿童Bartter综合征临床表现特点及诊断.方法收集本院1例及全国其他地区12例Bartter综合征患儿,对其发病情况,临床表现,实验室检查,治疗及预后等进行综合分析.结果儿童Bartter综合征以男性为多(9例).首发症状12例(92.3%)为多饮多尿.主要表现有①水、电解质及酸碱失衡,包括低钾血症、低钠血症、低氯性碱中毒及脱水等;②血肾素、血管紧张素Ⅱ及醛固酮等均明显升高,而血压正常;③生长发育迟滞较突出,其中4例有智力低下;④以消炎痛,安体舒通及补钾等综合治疗效果显著.结论儿童Bartter综合征首发症状多为多饮多尿.低钾血症,低氯性碱中毒,肾素、血管紧张素Ⅱ及醛固酮等升高,血压正常,有诊断价值.     

Erythrocyte sodium-potassium transport in cystic fibrosis.

Erythrocytes from 15 patients with cystic fibrosis (CF) aged 8 mo to 22 y (mean age 12.8 y) were analyzed for Na+,K(+)-ATPase activity and sodium, potassium, and ATP concentrations. Sodium concentrations and Na(+)-K+ ratio of erythrocytes were statistically significantly lower in the CF patients [6.6 (SD 1.9) versus 9.2 (SD 1.1) mmol/L (p less than 0.01) and 0.070 (SD 0.023) versus 0.104 (SD 0.016) mmol/L (p less than 0.01), respectively]. The Na+,K(+)-ATPase activity was similar compared with that of reference individuals [536 (SD 100) versus 488 (SD 92) nmol inorganic phosphate/mg protein/h]. Intraerythrocyte sodium concentration and Na(+)-K+ ratio were thus lower in relation to the recorded Na+,K(+)-ATPase activities in controls, indicating a change of the passive transmembrane movements of sodium ions in CF. There was a rise of erythrocyte sodium and Na(+)-K+ ratio despite unchanged Na+,K(+)-ATPase activity after regular infusion of a fat emulsion rich in essential fatty acids, inferring that an altered membrane composition by essential fatty acid deficiency could explain the low intracellular sodium concentration in CF.