Role of ergothioneine on S-nitrosoglutathione catabolism

Ergothioneine (ESH) is a low-molecular-mass thiol present in millimolar con centrations in a limited number of tissues, including erythrocytes, kidney, seminal fluid and liver; however, its biological function is still unclear . In the present study we investigated the role of ESH in the catabolism of S-nitroso-glutathione (GSNO). The results show that: (1) GSNO decompositio n is strongly influenced by ESH (k" = 0.178 +/- 0.032 M(-1)s(-1)); (2) ammo nia is the main nitrogen-containing compound generated by the reaction; and (3) nitrite is practically absent under both aerobic and anaerobic conditi ons. These findings are markedly different from those reported for the GSH- induced decomposition of GSNO, in which the nitrogen-containing end product s are nitrite, ammonia and nitrous oxide (N2O) under aerobic conditions but nitrite, ammonia, nitric oxide (NO) and small quantities of hydroxylamine under anaerobic conditions, Considering the high concentration of ESH in sp ecific cells, the reaction with GSNO should be considered as an important m olecular event occurring in the cell.