The kinetics of the reactions between sodium nitrite and phenol or m-, o-, or p-cresol in potassium hydrogen phthalate buffers of pH 2.5–5.7 were determined by integration of the monitored absorbance of the C-nitroso reaction products. At pH . 3, the dominant reaction was C-nitrosation through a mechanism that appears to consist of a diffusion-controlled attack on the nitrosatable substrate by ...

It is now about three decades since the hepatocarcinogenic effect of N-nitrosodimethylamine (NDMA)* was demonstrated in rats (1) and the suggestion was made that N-nitrosamines can be formed following nitrosation of various amines (2). Direct proof that such nitrosation reactions can occur was provided by Ender et al. (3) who identified NDMA in nitrite preserved fish-meal, and by Sander and Sei...

A 24 hour gastric aspiration study was carried out on nine Polya gastrectomy, eight pernicious anaemia, and nine matched control subjects. Intragastric pH, bacteria, nitrite, and N-nitroso compounds were assessed half hourly whilst ambulant and hourly when in bed. Both total and nitrate reducing bacterial counts were positively related to pH (chi 2 = 279.3; p less than 0.001), as was nitrite co...

The formation of /V-nitroso compounds in mouse stom ach from equimolar doses of sodium nitrite and secondary amines or alkylurea derivatives given simultaneously by a stomach tube was estimated by measuring the mutagenic activity of the compounds in the i.p. host-mediated assay with the use of Salmonella typhimurium TA1950 as genetic indicator system. A mutagenic response in the bacteria was fo...

Apurinic/apyrimidinic endonuclease 1/redox effector factor-1 (APE1/Ref-1, abbreviated as APE1) is a molecule with dual functions in DNA repair and redox regulation of transcription factors. Accumulated work has shown that the biological activities of APE1 are sensitive to oxidative stress; however, whether APE1 functions can be regulated by nitrosative stress remains unknown. In this investigat...

The hypothesis that intragastric synthesis of N-nitroso compounds (NOC) in early life could play a role in gastric carcinogenesis was tested by applying the N-nitrosoproline (NPRO) test to about 50 children living in high- and low-risk areas for stomach cancer in Costa Rica. The median values of excretion of NPRO and the sum of three nitrosamino acids (micrograms/12 h urine) were 10-20% of thos...

Ca 2+-Calmodulin (CaM) kinase II (CaMKII) activation depends predominantly on modifications of amino acids within the regulatory domain on this multidomain kinase. A number of mechanisms of activation have been described since the original mode of activation, via Ca 2+ /CaM binding and phosphorylation of a threonine residue in the regulatory domain of CaMKII, was demonstrated. In this issue of ...

BACKGROUND AND AIMS When saliva, with its high nitrite content derived from the enterosalivary recirculation of dietary nitrate, meets acidic gastric juice, the nitrite is converted to nitrous acid, nitrosative species, and nitric oxide. In healthy volunteers this potentially mutagenic chemistry is focused at the gastric cardia. We have studied the location of this luminal chemistry in Barrett'...

Unlike the formation of nitrosothiols by nitrous acid, our study revealed that NO2- effectively reacted with L-cysteine or reduced glutathione (GSH) at pH 7.0 and 7.4, to form orange-pink products of S-nitrosocysteine (CySNO) or S-nitrosoglutathione (GSNO). The reactions were in a concentration-dependent manner. These products exhibited not only peak absorbances at around 340 and 540 nm, but al...