Glutathione circadian rhythm in duodenal mucosa of fasted rats.

Duodenal ulcer is a relevant clinical condition, but information about circadian rhythms of the duodenum is scarce. While the chronobiological model of gastric ulcerogenesis has been partly demonstrated, the time dependent variations of protective and aggressive factors of the duodenal mucosa have not yet been sufficiently documented. The aim of this study is to document the duodenal mucosa circadian dynamics of glutathione (GSH), a sulfhydryl compound, a well-known intracellular protective agent. Male Wistar rats, 8-9 weeks of age, were maintained at controlled temperature and humidity and 12L:12D day cycle since birth. Duodenal mucosa samples obtained by scraping were assayed with a spectrophotometric method. The data analysis with the Cosinor method demonstrated circadian rhythmicity for GSH content in the duodenal mucosa with higher levels during the dark period.