title: New fluorescent probes E3810 and methoxy E3810 for determining distributions of the apical membrane and the acidic compartment of gastric acid secreting cells.
abstract: Substituted benzimidazoles such as omeprazole, E3810 and methoxy E3810 were inhibitors of gastric H+, K(+)-ATPase which is rich in the apical membrane of gastric parietal or oxyntic cells at the secreting state. The acid-activated compounds of omeprazole and methoxy E3810, which have methoxy group at the 5-position in the benzimidazole ring, are fluorescent (excitation wavelength = 370 nm; emission wavelength = 560 nm). The fluorescence disappeared when the activated compounds reacted with the ATPase or glutathione. Using this fluorescence property, the distribution of the intracellular acidic canalicular space in isolated single parietal cells was determined. On the other hand, irradiation with ultraviolet light (335 nm) of the acid-activated compound of E3810 which had been reacted with sulfhydryl group of the ATPase or glutathione resulted in a formation of a fluorescent compound (emission = 470 nm). Using this second fluorescence property, we determined the distribution of the apical membrane of the intracellular canaliculus of isolated single mammalian parietal cells and also the location of the apical membrane on the external surface of newt oxyntic cells.
authors.affiliation: Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Takeguchi
authors.forename: T
authors.initials: T
authors.lastname: Yamanouchi
authors.forename: H
authors.initials: H
authors.lastname: Sakai
authors.forename: M
authors.initials: M
authors.lastname: Morii
mesh_terms: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors; D000818:Animals; D001562:Benzimidazoles; D002462:Cell Membrane / Q000378:metabolism; D005456:Fluorescent Dyes; D005744:Gastric Acid / Q000378:metabolism*; D005753:Gastric Mucosa / Q000166:cytology / Q000378:metabolism*; D006168:Guinea Pigs; D017506:H(+)-K(+)-Exchanging ATPase; D066298:In Vitro Techniques; D009853:Omeprazole; D010295:Parietal Cells, Gastric / Q000378:metabolism; D011817:Rabbits; D064750:Rabeprazole; D012455:Salamandridae
chemical_list: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D001562:Benzimidazoles; D005456:Fluorescent Dyes; D064750:Rabeprazole; D000251:Adenosine Triphosphatases; D017506:H(+)-K(+)-Exchanging ATPase; D009853:Omeprazole