title: Conventionalization of germ-free rats reverses the disability of rhein anthrone to induce laxation.
abstract: This study shows that rhein anthrone has no laxative potency in germ-free rats because after intracaecal administration of a dose of 50 mg/kg the large intestine transit exceeded 240 min. The time course of the laxative potency of rhein anthrone injected intracaecally was evaluated after peroral inoculation of germ-free rats with the caecal contents of conventional rats. Large intestine transit was measured at consecutive periods, on days 0, 1, 2, 3 and 5 after peroral inoculation. It appeared that 1 day after peroral inoculation the laxative potency of rhein anthrone was already established (large intestinal transit < 10 min) and laxation remained on the following days (days 2, 3 and 5). We concluded that rhein anthrone is inactive in germ-free rats and acquires laxative potency after peroral inoculation of germ-free rats with caecal contents of conventional rats.
authors.affiliation: Laboratory of Pharmaceutical Biology and Phytopharmacology, Institute of Pharmaceutical Sciences, K.U. Leuven, Belgium.
authors.forename: G
authors.initials: G
authors.lastname: Nijs
authors.forename: P
authors.initials: P
authors.lastname: De Witte
authors.forename: K
authors.initials: K
authors.lastname: Geboes
authors.forename: J
authors.initials: J
authors.lastname: Mertens
authors.forename: H
authors.initials: H
authors.lastname: Eyssen
mesh_terms: D000818:Animals; D000873:Anthracenes / Q000494:pharmacology*; D001835:Body Weight / Q000187:drug effects; D002400:Cathartics / Q000494:pharmacology*; D005772:Gastrointestinal Transit / Q000187:drug effects*; D005856:Germ-Free Life; D007420:Intestine, Large / Q000187:drug effects / Q000382:microbiology; D008297:Male; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D011916:Rats, Inbred F344; D017208:Rats, Wistar; D000095322:Anthrones
chemical_list: D000873:Anthracenes; D002400:Cathartics; C055876:rhein-9-anthrone; D000095322:Anthrones