De Flora S, Picciotto A, Savarino V, Bennicelli C, Camoirano A, Garibotto G, Celle G
Institute of Hygiene, University of Genoa, Italy.
Mutagenesis. 1987 Mar;2(2):115-9. doi: 10.1093/mutage/2.2.115.
The circadian monitoring of intragastric pH and of the mutagenicity of 440 gastric juice samples collected hourly from 22 subjects provided evidence that, irrespective of diagnosis and treatment, a weak yet consistent increase in revertants can be detected in his- Salmonella typhimurium strains during the 3-4-h periods following each meal. The recorded mutagenic activity was not related to the histidine content of gastric juice, was due to thermostable components and was not significantly inhibited by administration of vitamin C. Various genetic mechanisms were involved, which were different from those consequent to the artificial supplementation of gastric juice with sodium nitrite. Treatment with a histamine H2-receptor antagonist (famotidine), either at dinner or at bedtime, was followed by a nocturnal plateau of mutagenicity. However, such effect was not due to mutagenicity of the drug or of its derivatives, but to the therapeutic rise in pH associated with its antisecretory activity.
对22名受试者每小时采集的440份胃液样本进行胃内pH值和致突变性的昼夜监测，结果表明，无论诊断和治疗情况如何，在每餐之后的3 - 4小时内，鼠伤寒沙门氏菌his - 菌株中的回复突变体均可检测到微弱但持续的增加。记录的诱变活性与胃液中的组氨酸含量无关，是由热稳定成分引起的，并且维生素C的给药并未对其产生显著抑制作用。涉及多种遗传机制，这些机制与通过向胃液中人工添加亚硝酸钠所导致的机制不同。在晚餐或就寝时使用组胺H2受体拮抗剂（法莫替丁）进行治疗后，夜间诱变活性出现平稳状态。然而，这种效应并非由于药物或其衍生物的诱变性，而是与其抗分泌活性相关的pH值治疗性升高所致。
