Kynurenine pathway

[5][2][6][7][8] Disorders affecting the kynurenine pathway may be primary (of genetic origin) or secondary (due to inflammatory conditions).

Patients with this disorder excrete excessive amounts of xanthurenic acid, kynurenic acid, 3-hydroxykynurenine, and kynurenine after tryptophan loading and are said to suffer from tachycardia, irregular breathing, arterial hypotension, cerebellar ataxia, developmental retardation, coma, renal tubular dysfunction, renal or metabolic acidosis, and even death.

The only biochemical abnormality noted in affected patients was a massive hyperkynureninuria, seen only during periods of coma or after intravenous protein loading.

[30][31][32][33][2][1] Changes in the ratio of kynurenine versus tryptophan are reported for many diseases like arthritis, HIV/AIDS, neuropsychiatric disorders,[1][6][2] cancer and inflammations.

These and subsequent derivatives are believed to be responsible for the biofluorescence observed in the skin of the swell shark and the chain catshark.