Ornithine Unit Converter

Ornithine is a non-proteinogenic amino acid, meaning it is not used to build proteins directly. Instead, it plays a central role in the urea cycle, the metabolic pathway the liver uses to convert toxic ammonia into urea for excretion.

Ornithine is produced in the body from the amino acid arginine via the enzyme arginase. It also serves as a precursor for polyamines (putrescine, spermidine, and spermine), which are essential for cell growth and division.

On a plasma amino acid profile, ornithine levels reflect the balance between its production from arginine and its consumption in the urea cycle and polyamine synthesis pathways.

Ornithine is produced primarily in the liver as part of the urea cycle, where the enzyme arginase converts arginine into ornithine and urea. Smaller amounts are generated in the kidneys and intestines.