Oxalate Absorption and Postprandial Urine Supersaturation in An Experimental Human Model of Absorptive Hypercalciuria
| Autor: | Peter G. Werness, J. W. Dobbins, Stephen B. Erickson, Arthur E. Broadus, Kerry Cooper, Henry J. Binder, Lynwood H. Smith |
|---|---|
| Rok vydání: | 1984 |
| Předmět: |
Adult
Male medicine.medical_specialty Calcium oxalate chemistry.chemical_element Calcium Oxalate Excretion chemistry.chemical_compound Calcitriol Calcium Metabolism Disorders Internal medicine medicine Crystalluria Humans Hypercalciuria Calcium metabolism Oxalates Calcium Oxalate Oxalic Acid Osmolar Concentration Fasting General Medicine medicine.disease Endocrinology Postprandial Intestinal Absorption chemistry Female medicine.symptom Crystallization Nuclear chemistry |
| Zdroj: | Clinical Science. 67:131-138 |
| ISSN: | 1470-8736 0143-5221 |
| DOI: | 10.1042/cs0670131 |
| Popis: | 1. The effect of 1,25-dihydroxyvitamin D [1,25-(OH)2D] on dietary oxalate absorption and postprandial urine supersaturation with calcium oxalate was determined in 11 normal subjects. 2. 1,25-(OH)2D increased the urinary excretion of orally administered [14C]oxalate in the 8 h period after a liquid meal containing 1.875 mmol of calcium and 0.83 mmol of oxalate (P < 0.01), and during a 48 h period when the subjects ingested a diet containing 25 mmol of calcium and 3.3 mmol of oxalate/day (P < 0.01); however, 1,25-(OH)2D administration had no effect on [14C]oxalate excretion when calcium was removed from the liquid meal. 3. 1,25-(OH)2D increased 24 h urinary oxalate excretion from 28.7 ± 2.1 mmol/mol of creatinine to 36.8 ± 2.6 mmol/mol of creatinine (P < 0.05) on the 10 mmol/day calcium diet and from 26.4 ± 2.9 to 33.2 ± 2.2 mmol/mol of creatinine (P < 0.1) on the 25 mmol/day calcium diet. 4. A linear correlation (r = 0.72) was found between plasma 1,25-(OH)2D levels and urinary [14C]oxalate excretion after the liquid meal. 5. 1,25-(OH)2D administration produced postprandial supersaturation of urine with calcium oxalate and calcium oxalate crystalluria. 6. These studies suggest that 1,25-(OH)2D increases oxalate absorption (and urinary excretion) by increasing calcium absorption, which results in less binding of calcium to oxalate in the intestine; therefore more oxalate is available for absorption. The combined effect of increased calcium and oxalate absorption results in postprandial supersaturation of urine with calcium oxalate, with resultant crystalluria. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|