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Updated: May 11, 2026
06:18
Optical Clearing and Imaging of Immunolabeled Kidney Tissue
Published on: July 22, 2019
Numerous protein-bound solutes are cleared by the kidney with high efficiency
Tammy L Sirich1, Pavel A Aronov, Natalie S Plummer
1Department of Medicine, VA Palo Alto HCS, Palo Alto, California 94303, USA. tsirich@stanford.edu
Kidney International
|May 3, 2013
Summary
Researchers identified key solutes efficiently cleared by healthy kidneys. These substances accumulate in patients with kidney failure, suggesting they may be uremic toxins and potential targets for improved dialysis therapies.
Area of Science:
- Nephrology
- Biochemistry
- Analytical Chemistry
Background:
- Kidney failure leads to solute retention and uremic illness.
- Identifying toxic retained solutes is crucial for improving dialysis.
- Current knowledge of which solutes are toxic is limited.
Purpose of the Study:
- To identify solutes efficiently cleared by the kidney.
- To investigate the mechanisms of efficient solute clearance.
- To determine if these efficiently cleared solutes accumulate in kidney failure.
Main Methods:
- Untargeted high-resolution mass spectrometry of urine and plasma ultrafiltrate.
- Estimation of solute clearance rates relative to creatinine and renal plasma flow.
- Quantitative mass spectrometry with stable isotope dilution.
- Tandem mass spectrometry for chemical identification.
Main Results:
- 1808 features detected; 1082 showed clearance exceeding creatinine clearance (tubular secretion).
- 90 features had clearance rates exceeding renal plasma flow, indicating efficient clearance mechanisms.
- 13 solutes identified, including hippuric acid, indoxyl sulfate, and p-cresol sulfate.
- These 13 solutes accumulated significantly in hemodialysis patients.
Conclusions:
- Efficient kidney clearance involves plasma protein binding and tubular secretion.
- Identified efficiently cleared solutes accumulate in kidney failure, suggesting potential uremic toxicity.
- Further study of these solutes may lead to the identification of novel uremic toxins.
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