A putative role for S-nitrosoglutathione as the source of nitric oxide in photorelaxation of the mouse gastric fundus.
Mouse gastric fundus strips were relaxed by ultraviolet light (UV) irradiation, exogenous nitric oxide (NO), isoproterenol, S-nitrosoglutathione, S-nitroso-L-cysteine and S-nitroso-N-acetyl-penicillamine. Glutathione did not affect relaxations in response to UV irradiation, exogenous NO and isoproterenol while inhibiting that with S-nitrosoglutathione. L-Cysteine inhibited responses to UV irradiation and exogenous NO, but not in the presence of exogenous Cu(2+)/Zn(2+) superoxide dismutase. However, L-cysteine alone or in combination with Cu(2+)/Zn(2+) superoxide dismutase did not affect the relaxations in response to S-nitroso-L-cysteine. Ethacrynic acid and diamide inhibited photorelaxations but not the relaxations with exogenous NO and isoproterenol. This inhibition was prevented by glutathione, but not by L-cysteine. S-nitrosoglutathione-induced relaxations were abolished by diamide and ethacrynic acid, whereas responses to S-nitroso-L-cysteine and S-nitroso-N-acetyl-penicillamine were only inhibited by ethacrynic acid. These results suggest that S-nitrosoglutathione may, at least in part, be the putative S-nitrosothiol, which is converted to NO in response to UV irradiation in mouse gastric fundus strips.
Department of Pharmacology, Faculty of Medicine, Cukurova University, 01330 Adana, Turkey. ogulener@mail.cu.edu.tr
Nuran
N
Ogülener
Yusuf
Y
Ergün
D000111:Acetylcysteine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D003545:Cysteine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D003958:Diamide / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004976:Ethacrynic Acid / Q000494:pharmacology; D005260:Female; D005748:Gastric Fundus / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects*; D005978:Glutathione / Q000494:pharmacology; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D051379:Mice; D009126:Muscle Relaxation; D009130:Muscle, Smooth / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D009569:Nitric Oxide / Q000378:metabolism*; D026422:S-Nitrosoglutathione / Q000378:metabolism* / Q000494:pharmacology; D026403:S-Nitrosothiols / Q000378:metabolism; D014466:Ultraviolet Rays
D004791:Enzyme Inhibitors; D026403:S-Nitrosothiols; D003958:Diamide; D009569:Nitric Oxide; C024940:S-nitroso-N-acetylcysteine; D026422:S-Nitrosoglutathione; C021315:S-nitrosocysteine; D005978:Glutathione; D003545:Cysteine; D007545:Isoproterenol; D004976:Ethacrynic Acid; D000111:Acetylcysteine