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Oxalate Concentrations in Human Gastrointestinal Fluid.
Thanmaya G Reddy1, John Knight1, Ross P Holmes1
11 Department of Urology, University of Alabama at Birmingham School of Medicine , Birmingham, Alabama.
This study found oxalate in the small intestine of fasted adults, suggesting potential secretion. Minimal oxalate was detected in the stomach, indicating the small intestine may play a role in oxalate regulation.
Area of Science:
- Gastroenterology
- Nephrology
- Human Physiology
Background:
- Urinary oxalate is a risk factor for kidney stones (nephrolithiasis).
- Oxalate originates from metabolism and diet, absorbed via the gastrointestinal tract.
- Evidence for oxalate secretion in the human gastrointestinal tract is currently lacking.
Purpose of the Study:
- To quantify oxalate levels and forms in the stomach and small intestine.
- To investigate potential gastrointestinal secretion of oxalate in humans.
Main Methods:
- Gastrointestinal fluid samples were collected from 11 adults during endoscopy.
- Oxalate was analyzed for soluble and insoluble components after centrifugation and acidification.
- Ion chromatography was used to measure oxalate concentration, with a detection limit of 1.6 μM.
Main Results:
- Oxalate was detected in most small intestine samples, but minimally in stomach samples.
- Small intestinal oxalate concentrations varied widely and included a higher proportion of insoluble forms.
- These findings contrast with the minimal oxalate found in the stomach.
Conclusions:
- Results suggest possible oxalate secretion in the fasted small intestine, but not significantly in the stomach.
- Further research is needed to confirm gastrointestinal oxalate secretion in humans.
- This study contributes to understanding oxalate homeostasis and its relation to nephrolithiasis.
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