Aminohippuric acid

Aminohippuric acid

Aminohippuric acid (also known as PAH) is a compound used in medicine and biology as a diagnostic agent and biological marker. It is an amide derivative of hippuric acid, and is often used in renal plasma flow (RPF) tests to measure the rate at which blood is delivered to the kidneys.

History

Aminohippuric acid was first synthesized in the early 20th century. Its use in medicine began in the 1940s, when it was discovered that it could be used to measure renal plasma flow.

Structure and Properties

Aminohippuric acid is a small, water-soluble molecule with a molecular weight of 194.19 g/mol. It is an amide derivative of hippuric acid, with an amino group replacing one of the hydrogen atoms on the benzene ring. This gives it a slightly polar character, allowing it to dissolve in water and be excreted by the kidneys.

Medical Uses

Aminohippuric acid is primarily used in medicine as a diagnostic agent. It is injected into the bloodstream, where it is rapidly filtered out by the kidneys and excreted in the urine. By measuring the concentration of aminohippuric acid in the urine and blood, doctors can calculate the rate of renal plasma flow, which is an important indicator of kidney function.

In addition to its use in renal plasma flow tests, aminohippuric acid is also used as a biological marker in studies of kidney function and drug metabolism. Because it is rapidly and almost completely excreted by the kidneys, it can be used to track the rate at which drugs or other substances are cleared from the body.

Safety and Side Effects

Aminohippuric acid is generally considered safe for use in medical testing. However, like all drugs, it can cause side effects in some people. These can include allergic reactions, nausea, and pain at the injection site.

See Also

• Hippuric acid
• Renal plasma flow
• Kidney function test