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High Concentrations of Ammonia, But Not Volatile Amines, in Gastric Juice of Subjects with Helicobacter pylori Infection
Author(s) -
Verdú Elena F.,
Armstrong David,
Sabovcikova Lionella,
Idström JanPeter,
Cederberg Christer,
Blum André L.,
Bercík Premysl
Publication year - 1998
Publication title -
helicobacter
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.206
H-Index - 79
eISSN - 1523-5378
pISSN - 1083-4389
DOI - 10.1046/j.1523-5378.1998.08068.x
Subject(s) - helicobacter pylori , ammonia , serial dilution , chemistry , dilution , chromatography , enzyme , medicine , gastroenterology , biochemistry , pathology , physics , alternative medicine , thermodynamics
Background.~ Helicobacter pylori ( H. pylori ) produces large amounts of ammonia. Based on higher readings obtained with an ammonia‐sensitive electrode when compared to a specific enzymatic assay, it has been claimed that H. pylori also produces potentially toxic volatile amines. Method. We measured ammonia concentrations (NH 3 ) in gastric aspirates from 11 H. pylori positive subjects (22–40 y, 6~ m ), using an ammonia electrode sensitive to ammonia and amines, and an enzymatic assay specific for ammonia. Continuous aspiration was performed overnight and 220 aspirates were analyzed before and 6~weeks after cure of H. pylori. Gastric samples were diluted 1:3 (before cure) and 1:1 (after cure) according to dilution curves constructed prior to the assays. Results. Median (95% CI) NH 3 detected by the elec‐trode/enzymatic assay were 4.34~m m [4.12–4.61]/4.50~m m [4.28–4.68] ( p~ >~.05) before cure and 0.54~m m [0.42–0.60]/0.73~m m [0.71–0.81] after cure ( p~ >~.05). Intra‐class correlation coefficient between the two methods was 0.91 before cure and 0.90 after cure ( p~ <~.001). Without dilution, the enzymatic assay was linear for NH 3 from 0.01 to 1~m m and saturated at 2.5~m m ; the electrode was linear for NH 3 from 0.01 to 20~m m . When appropriate dilutions were performed, the enzymatic assay was accurate for NH 3 greater than 2.5~m m . Conclusion. In subjects with H. pylori infection there is a high NH 3 in gastric juice; production of volatile amines appears to be negligible in vivo . An ammonia‐sensitive electrode and a specific enzymatic assay are both suitable methods for determining NH 3 in the gastric juice of subjects with H. pylori infection.