First pass effect of 1-naphthol in the gastric mucosa. Studies with isolated epithelium and cultured mucous cells of guinea pig.
Disposition of 1-[14C]naphthol was investigated in stripped gastric mucosal segments mounted in Ussing chambers. During 2-hr incubations, naphthol was glucuronidated (44-55% of added dose) and sulfated (7-15%). When naphthol was added to the luminal fluid at pH 7.0, conjugates were released with equal velocity to the luminal and to the vascular side, but with a luminal pH of 3, conjugates appeared predominantly on the vascular side. When naphthol was added to the vascular side (both sides pH 7), conjugates appeared predominantly on the vascular side. Cultured gastric mucous cells formed naphthol glucuronide and naphthol sulfate at a ratio of 9:1. These conjugates were transiently accumulated within cells up to 300-fold followed by slow release into the medium. In conclusion, the intact gastric mucosa is able to conjugate 1-naphthol at neutral and acidic luminal pH. The data suggest that ingested phenolic compounds might be modified by a gastric first pass effect.
Schwenk
M
M
Abteilung Allgemeine Pharmakologie, Medizinische Hochschule Hannover, Germany.
Linz
C
C
Rechkemmer
G
G
D000818:Animals; D002478:Cells, Cultured / Q000378:metabolism; D004848:Epithelium / Q000378:metabolism; D005753:Gastric Mucosa / Q000378:metabolism*; D005965:Glucuronates / Q000378:metabolism; D006168:Guinea Pigs; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008297:Male; D009284:Naphthols / Q000493:pharmacokinetics*
D005965:Glucuronates; D009284:Naphthols; C029350:1-naphthol