Idiopathic hypercalciuria is a common disorder whose inheritance suggests an enzyme abnormality in calcium transport. We measured calcium-magnesium-ATPase activity in erythrocytes from 38 patients (mean age [+/- SEM], 40 +/- 2.1 years) with idiopathic hypercalciuria (24-hour urinary calcium excretion greater than or equal to 0.1 mmol per kilogram of body weight) and a history of multiple calcium oxalate kidney stones. As compared with 41 healthy controls, the patients with hypercalciuria had increased erythrocyte-membrane calcium-magnesium-ATPase activity (64.2 +/- 2.19 vs. 51.6 +/- 1.91 nmol of ATP split per milligram per minute; P less than 0.01) and increased sodium-potassium pump activity (6866 +/- 233 vs. 6096 +/- 228 mumol of sodium per liter of red cells per hour; P less than 0.05). No significant difference between the two groups was found in erythrocyte sodium-potassium cotransport, sodium-lithium countertransport, or potassium content. In 66 patients with kidney stones (38 with hypercalciuria and 28 with normal calcium excretion), 24-hour urinary calcium excretion correlated with calcium-magnesium-ATPase activity (r = 0.46, P less than 0.001). Erythrocyte calcium-magnesium-ATPase activity remained unchanged in eight subjects studied after four months on a low-calcium diet. A study of 30 healthy families found significant correlations between mean values in parents and those in offspring for calcium-magnesium-ATPase (r = 0.68, P less than 0.001) and urinary calcium excretion (r = 0.45, P less than 0.02), with no significant correlations between parents with respect to these measures (r = 0.27 and r = 0.08, respectively). We conclude that abnormalities in erythrocyte calcium-magnesium-ATPase activity may represent an inherited defect in calcium transport related to the cause of idiopathic hypercalciuria.
Abnormal red-cell calcium pump in patients with idiopathic hypercalciuria / G. Bianchi, G. Vezzoli, D. Cusi, T. Cova, A. Elli, L. Soldati, G. Tripodi, M. Surian, E. Ottaviano, P. Rigatti, S. Ortolani. - In: NEW ENGLAND JOURNAL OF MEDICINE. - ISSN 0028-4793. - 319:14(1988 Oct 06), pp. 897-901.
|Titolo:||Abnormal red-cell calcium pump in patients with idiopathic hypercalciuria|
|Settore Scientifico Disciplinare:||Settore MED/14 - Nefrologia|
|Data di pubblicazione:||6-ott-1988|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1056/NEJM198810063191402|
|Appare nelle tipologie:||01 - Articolo su periodico|