Determination of S-[2-carboxy-1-(1H-imidazol-4-yl)ethyl]glutathione, a novel metabolite of L-histidine, in tissue extracts from sunlight-irradiated rat by capillary electrophoresis

Citation
M. Kinuta et al., Determination of S-[2-carboxy-1-(1H-imidazol-4-yl)ethyl]glutathione, a novel metabolite of L-histidine, in tissue extracts from sunlight-irradiated rat by capillary electrophoresis, ELECTROPHOR, 22(16), 2001, pp. 3365-3370
Citations number
19
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Chemistry & Analysis
Journal title
ELECTROPHORESIS
ISSN journal
0173-0835 → ACNP
Volume
22
Issue
16
Year of publication
2001
Pages
3365 - 3370
Database
ISI
SICI code
0173-0835(200110)22:16<3365:DOSAN>2.0.ZU;2-6
Abstract
Exposure of the skin to sunlight results in an increase in the content of e pidermal Urocanic acid, a key metabolite Of L-histidine, and some portions of the metabolite penetrate into the body fluid. S-[2-Carboxy-1 -(1H-imidaz ol-4-yl)ethyl]glutathione (GS(CIE)), an adduct of glutathione and urocanic acid, was proposed to be an origin of a urinary compound, S-[2-carboxy-1-(1 H-imidazol-4-yl)ethyl]-L-cysteine (Cys(CIE)). Various catabolites of Cys(CI E) were also isolated from human urine previously. However, no direct evide nce to show the existence of GS(CIE) as a biological material had been foun d. By using capillary electrophoresis, the glutathione adduct has now been found in the extracts of rat tissues from the kidney, liver, skin and blood when the rat was kept under conditions of sunlight irradiation after the f ur on the dorsal skin had been clipped. On the other hand, no or a trace of GS(CIE) was determined in rat tissue extracts when the animal was kept ind oor in usual manner. The glutathione adduct was isolated from the kidney ex tract of the sunlight-irradiated rat using ion-exchangers and high-voltage paper electrophoresis, and determined by fast-atom-bombardment mass spectro metry. These results indicate that GS(CIE) formation actually occurs in the body and that the formation is accelerated by exposing the rat to sunlight irradiation. From these findings, we propose an alternative pathway of his tidine metabolism which is initiated by the adduction of urocanic acid to g lutathione to form GS(CIE) and terminates with the formation of the urinary compounds via Cys(CIE).