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Melatonin and its precursors scavenge nitric oxide
Author(s) -
Noda Y.,
Mori A.,
Liburdy R.,
Packer L.
Publication year - 1999
Publication title -
journal of pineal research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.881
H-Index - 131
eISSN - 1600-079X
pISSN - 0742-3098
DOI - 10.1111/j.1600-079x.1999.tb00611.x
Subject(s) - melatonin , nitric oxide , chemistry , griess test , scavenging , tryptophan , serotonin , scavenger , biochemistry , nitrite , medicine , organic chemistry , radical , nitrate , receptor , amino acid , antioxidant
Nitric oxide (NO) scavenging activity of melatonin, N‐acetyl‐5‐hydroxytryptamine, serotonin, 5‐hydroxytryptophan and L‐tryptophan was examined by the Griess reaction using flow injection analysis. l‐Hydroxy‐2‐oxo‐3‐(N‐methyl‐3‐aminopropyl)‐3‐methyl‐1 ‐ triazene (NOC‐7) was used as NO generator. The Griess reagent stoichiometrically reacts with NO 2 , which was converted by a cadmium‐copper reduction column from the stable end products of NO oxidation. Except for tryptophan, all the compounds examined scavenged NO in a dose‐dependent manner. Melatonin, which has a methoxy group in the 5‐position and an acetyl side chain, exhibited the most potent scavenging activity among the compounds tested. Serotonin. N‐acetyl‐5 hydroxytryptamine, and 5‐hydroxytryptophan, respectively, showed moderate scavenging activity compared to melatonin. Tryptophan, which has neither a methoxy nor a hydroxyl group in the 5‐position, exhibited the least NO scavenging activity.