Showing chemical card for Creatinine (CFc000000438)
Record Information
Version
1.0
Creation Date
2022-08-28 10:25:12 UTC
Update Date
2022-09-13 18:44:49 UTC
Chemfont ID
CFc000000438
Molecule Identification
Common Name
Creatinine
Definition
Creatinine or creatine anhydride is a member of the class of compounds known as imidazolidinones. Imidazolidinones are a class of 5-membered ring heterocycles structurally related to imidazole. Creatinine can also be classified as an amino acid derivative. Creatinine arises from the production of creatine. Creatine is synthesized primarily in the liver from the methylation of guanidino acetate by S-Adenosyl methionine (SAM). Guandino acetate is synthesized in the kidney from the amino acids arginine and glycine. Creatine is then phosphorylated to become the high-energy compound known as phosphocreatine. Creatine conversion to phosphocreatine is catalyzed by the enzyme creatine kinase. Creatinine is spontaneously formed during this reaction. In particular, the loss of a water molecule from creatine results in the formation of creatinine. Creatinine is transferred to the kidneys by blood plasma, whereupon it is eliminated from the body by glomerular filtration and partial tubular excretion. Creatinine is usually produced at a fairly constant rate by the body, which is roughly proportional to muscle mass and body size. Men are larger and generally have greater muscle mass than women, so men generally produce more creatinine than women. The typical reference range for creatinine in blood (plasma or serum) for women is about 45-90 µmol/L; for men 60-110 µmol/L. Creatinine levels in urine roughly correspond to the levels in serum with men generally producing more creatinine in their urine (7-16 mmol/L in men vs. 5-12 µmol/L in women). Creatinine is considered a waste product and is normally eliminated in large quantities by the kidneys through urinary excretion. Inefficient kidney/glomerular filtration will lead to elevated levels of creatinine in the serum. Measuring serum creatinine is a simple test and it is the most commonly used indicator of renal function. A rise in blood creatinine levels is observed only with marked damage to functioning nephrons in the kidney. Therefore, the serum creatinine test is not ideal for detecting early kidney disease. Levels of creatinine >120 µmol/L are suggestive of kidney injury or kidney failure, which may arise during sepsis, serious kidney infections or certain viral infections (COVID-19). Loss of kidney function can lead to the release of many pro-inflammatory compounds and uremic toxins into the blood stream, leading to further complications for those who are already ill. Other measures of kidney function involve the measurement of creatinine over sustained periods of time to determine the glomerular filtration rate (GFR) and the creatinine clearance. Creatine and creatinine are metabolized in the kidneys, muscle, liver, and pancreas. Recent studies have suggested that creatinine can be effective at killing bacteria of many species in both the Gram positive and Gram negative as well as diverse antibiotic resistant bacterial strains (PMID: 22293916 ). The mechanism by which creatinine kills bacteria is not presently known although it may serve to prevent urinary tract infections. A recent report also suggests that creatinine may have immunosuppressive properties (PMID: 21575742 ).
Belongs to the class of organic compounds known as alpha amino acids and derivatives. These are amino acids in which the amino group is attached to the carbon atom immediately adjacent to the carboxylate group (alpha carbon), or a derivative thereof.
Reddick, Rebecca E.; Kenyon, George L. Syntheses and NMR studies of specifically labeled [2-15N]phosphocreatine, [2-15N]creatinine, and related 15N-labeled compounds. Journal of the American Chemical Society (1987), 109(14), 4380-7.
