Renal clearance ratio
Encyclopedia
The renal clearance ratio or fractional excretion is a measure of the speed at which a constituent of urine
passes through the kidney
s. It is defined by following equation:
Creatinine
is sometimes used instead of inulin as the reference substance.
Urine
Urine is a typically sterile liquid by-product of the body that is secreted by the kidneys through a process called urination and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream...
passes through the kidney
Kidney
The kidneys, organs with several functions, serve essential regulatory roles in most animals, including vertebrates and some invertebrates. They are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and...
s. It is defined by following equation:
- X is the analyteAnalyteAn analyte, or component , is a substance or chemical constituent that is of interest in an analytical procedure. Grammatically, it is important to note that experiments always seek to measure properties of analytes—and that analytes themselves can never be measured. For instance, one cannot...
substance - Cx is the renal plasma clearance of X
- Cin is the renal plasma clearance of inulinInulinInulins are a group of naturally occurring polysaccharides produced by many types of plants. They belong to a class of fibers known as fructans. Inulin is used by some plants as a means of storing energy and is typically found in roots or rhizomes...
.
Creatinine
Creatinine
Creatinine is a break-down product of creatine phosphate in muscle, and is usually produced at a fairly constant rate by the body...
is sometimes used instead of inulin as the reference substance.