Urinary Clearance
Urinary Clearance - Related Videos
08:13
Evaluation of Zebrafish Kidney Function Using a Fluorescent Clearance Assay
0 Views •
Cited by 29 •
2015
The zebrafish is a popular tool to model chronic kidney disease (CKD). However, their small size makes it impossible to evaluate renal function using traditional methods. We describe a fluorescent dye kidney clearance assay1 that allows quantitative analysis of zebrafish kidney function in CKD.
03:47
Methylene Blue Dye Injection in Mouse Embryonic Urinary Tract: A Method To Assess the Congenital Obstruction in the Urinary Tract
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2025
In this video, we administer methylene blue dye injection into the urinary tract of a perinatal embryonic mouse to assess congenital anomalies related to urinary tract obstruction.
01:09
Hepatic Drug Clearance: Restrictive and Nonrestrictive Clearance
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2025
Hepatic clearance refers to the volume of blood cleared of a drug by the liver per unit of time. It plays a crucial role in drug metabolism and elimination. While hepatic clearance is commonly estimated by subtracting renal clearance from total body clearance, other pathways, such as pulmonary or biliary clearance, may also contribute. However, these pathways are generally less significant than hepatic and renal clearance. Most drugs undergo restrictive clearance, which is proportional to the...
05:05
A Modified Precipitation Method to Isolate Urinary Exosomes
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Cited by 32 •
2015
This manuscript describes a protocol for isolating exosomes from human urine using a modified precipitation technique.
02:53
Generating Urinary Tract Infection Model: A Technique to Administer Uropathogenic Bacteria in Mouse to Develop Urinary Tract Infection Model
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2025
In this video, we describe the technique for the intravesical administration of uropathogenic bacteria to generate a urinary tract infection model in mice. This model can be used to understand the spread of uropathogenic bacterial infection within the urinary system and the mechanisms that determine UTI susceptibility.
FAQs
Urinary clearance is calculated by multiplying the urine concentration of a substance by its urine flow rate, then dividing that excretion rate by the substance’s plasma concentration. This relationship connects laboratory measurements to kidney handling: a higher urinary excretion rate or lower plasma concentration produces a higher calculated clearance, provided the measurements are interpreted together.
Glomerular filtration provides the starting point, but tubular transport can alter the final urinary amount. Tubular secretion adds substance to the forming urine and can increase clearance, whereas tubular reabsorption removes substance from the tubular fluid and lowers clearance. Consequently, clearance reflects the combined renal handling processes rather than filtration alone.
Creatinine clearance is useful clinically because it helps estimate glomerular filtration and assess kidney performance. Inulin provides a comparison marker for examining filtration efficiency. Placing these measurements in context helps distinguish an estimate of filtration from a reference approach used to clarify how effectively the kidneys filter plasma.
Neither measurement should be interpreted in isolation. The urine excretion rate indicates how much substance the kidneys eliminate over time, while the plasma concentration supplies the circulating amount against which that elimination is assessed. Changes in either value can alter the calculated clearance, so paired measurements are necessary for meaningful interpretation.
The calculation requires the substance’s concentration in urine, the rate at which urine is excreted, and its concentration in plasma. These values are combined mathematically to obtain clearance for that substance. In clinical evaluation, the resulting measure can then be considered alongside creatinine or inulin findings to assess renal filtration and kidney performance.
Clearance measurements provide a quantitative way to evaluate how effectively the kidneys handle a substance. Creatinine clearance can help estimate glomerular filtration and identify reduced kidney performance, while comparison with inulin may add context about filtration efficiency. These findings support clinical assessment of renal impairment rather than relying only on a single concentration measurement.
Kidney clearance measurements help clinicians interpret how changes in renal function may affect drug elimination. When clearance decreases, medication handling may differ from expected patterns, making renal function relevant to dose adjustment. This application connects urinary clearance with practical treatment decisions, particularly when impaired kidney performance could alter the way a drug is eliminated.