Esophageal acid exposure at pHor = 2 is more common in Barrett's esophagus patients and is associated with oxidative stress
| Autor: | Harris Bernstein, Harinder S. Garewal, M. Chavarria, Katerina Dvorak, Barbora Dvorakova, Carol Bernstein, Ronnie Fass, Claire M. Payne, R. Dekel |
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| Rok vydání: | 2006 |
| Předmět: |
Male
medicine.medical_specialty Esophageal pH Monitoring Esophageal Neoplasms Adenocarcinoma medicine.disease_cause Gastroenterology Cell Line Barrett Esophagus Internal medicine medicine Esophagitis Humans Esophagus chemistry.chemical_classification Reactive oxygen species medicine.diagnostic_test business.industry Reflux Epithelial Cells General Medicine Middle Aged medicine.disease Flow Cytometry Oxidative Stress medicine.anatomical_structure chemistry Microscopy Fluorescence Apoptosis Barrett's esophagus Gastric acid Female Esophagoscopy business Esophageal pH monitoring Reactive Oxygen Species Oxidative stress |
| Zdroj: | Diseases of the esophagus : official journal of the International Society for Diseases of the Esophagus. 19(5) |
| ISSN: | 1120-8694 |
| Popis: | Barrett's esophagus (BE) patients demonstrate a higher distal esophageal acid exposure profile than other gastroesophageal reflux disease patients. Cellular oxidative stress has been proposed to contribute to the development of BE and esophageal adenocarcinoma. However, a relationship between low esophageal pH and oxidative stress has yet to be elucidated. The aim of this study was to determine the duration of low pH exposure in the esophagus of BE patients compared to those with erosive esophagitis (EE) and to test if brief exposure to low pH leads to the induction of reactive oxygen species (ROS). Seventy-three patients with BE or EE were evaluated by 24-hour esophageal pH monitoring and the percentage of time during which there was exposure to pH < or = 4 and pH < or = 2 was recorded. In vitro, Seg-1 and Het-1A cells were evaluated after brief exposure to pH4 or pH2 by flow cytometry and fluorescent microscopy for the production of ROS. BE patients demonstrated a significantly higher exposure to low pH values (pH < or = 2) than EE patients. The mean percent total time, duration and mean number of reflux episodes at pH < or = 2 were 2.8 +/- 0.53%, 28.8 +/- 3.6 seconds and 79 +/- 11.4 episodes in BE patients, whereas in EE patients they were significantly less, 1.16 +/- 0.3%, 15.6 +/- 1.2 seconds and 48.3 +/- 8.8 episodes, respectively (P < 0.05). In vitro experiments indicate that esophageal cells, when exposed to pH 2, produce ROS. In vitro studies using brief pH 2 exposure are biologically relevant to the clinical situation. Our studies indicate that such exposure induces oxidative stress. This stress may cause DNA damage, mutations and progression to cancer. |
| Databáze: | OpenAIRE |
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