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Alkali absorption and citrate excretion in calcium nephrolithiasisThe role of net gastrointestinal (GI) alkali absorption in the development of hypocitraturia was investigated. The net GI absorption of alkali was estimated from the difference between simple urinary cations (Ca, Mg, Na, and K) and anions (Cl and P). In 131 normal subjects, the 24 h urinary citrate was positively correlated with the net GI absorption of alkali (r = 0.49, p < 0.001). In 11 patients with distal renal tubular acidosis (RTA), urinary citrate excretion was subnormal relative to net GI alkali absorption, with data from most patients residing outside the 95% confidence ellipse described for normal subjects. However, the normal relationship between urinary citrate and net absorbed alkali was maintained in 11 patients with chronic diarrheal syndrome (CDS) and in 124 stone-forming patients devoid of RTA or CDS, half of whom had "idiopathic" hypocitraturia. The 18 stone-forming patients without RTA or CDS received potassium citrate (30-60 mEq/day). Both urinary citrate and net GI alkali absorption increased, yielding a significantly positive correlation (r = 0.62, p < 0.0001), with the slope indistinguishable from that of normal subjects. Thus, urinary citrate was normally dependent on the net GI absorption of alkali. This dependence was less marked in RTA, confirming the renal origin of hypocitraturia. However, the normal dependence was maintained in CDS and in idiopathic hypocitraturia, suggesting that reduced citrate excretion was largely dietary in origin as a result of low net alkali absorption (from a probable relative deficiency of vegetables and fruits or a relative excess of animal proteins).
Document ID
20050000449
Document Type
Reprint (Version printed in journal)
Authors
Sakhaee, K. (University of Texas Southwestern Medical Center Dallas)
Williams, R. H.
Oh, M. S.
Padalino, P.
Adams-Huet, B.
Whitson, P.
Pak, C. Y.
Date Acquired
August 22, 2013
Publication Date
July 1, 1993
Publication Information
Publication: Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research
Volume: 8
Issue: 7
ISSN: 0884-0431
Subject Category
Aerospace Medicine
Funding Number(s)
CONTRACT_GRANT: M01-RR00633
CONTRACT_GRANT: P01-DK20543
Distribution Limits
Public
Copyright
Other
Keywords
Non-NASA Center
NASA Discipline Number 18-10
NASA Center JSC
NASA Program Space Physiology and Countermeasures
NASA Discipline Regulatory Physiology