title: Circadian rhythm in prostacyclin activity in gastric tissue of the fasting rat.
abstract: Gastroduodenal ulcer disease may result from the desynchronization of the circadian rhythms of gastric protective and destructive factors. The purpose of this study was to evaluate whether gastric tissue 6-keto prostaglandin F1 alpha (PGF1 alpha), a catabolic derivative of the putative protective factor prostacyclin, is produced in a circadian fashion in the rat model. Forty-eight male Sprague-Dawley rats were acclimatized in sound-attenuated, lightproof chambers for 3 weeks on a 12:12 hour light/dark entrainment schedule. After an 18-hour fast, six rats were killed at each of eight sampling times. The stomachs were exposed, removed, and assayed for total 6-keto PGF1 alpha content by radioimmunoassay. Cosinor analysis of the data showed significant (p = 0.0262) circadian rhythmicity in 6-keto PGF1 alpha content with an acrophase (peak time) value of 0503 HALO (hours after lights on) or in the middle of the lights-on inactive period for the rats. Hypothetically, the circadian rhythm in some gastric protective factors may render the gastric mucosa vulnerable to injury in a circadian fashion.
authors.affiliation: Salt Lake City Veterans Administration Medical Center, Department of Medicine, Utah 84148.
authors.forename: J G
authors.initials: JG
authors.lastname: Moore
authors.forename: M D
authors.initials: MD
authors.lastname: Mitchell
authors.forename: K R
authors.initials: KR
authors.lastname: Larsen
authors.forename: M T
authors.initials: MT
authors.lastname: Dayton
mesh_terms: D015121:6-Ketoprostaglandin F1 alpha / Q000378:metabolism*; D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology*; D005215:Fasting / Q000378:metabolism; D005753:Gastric Mucosa / Q000378:metabolism* / Q000502:physiology; D008297:Male; D010437:Peptic Ulcer / Q000209:etiology; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D015121:6-Ketoprostaglandin F1 alpha