title: Geranylgeranylacetone protects membranes against nonsteroidal anti-inflammatory drugs.
abstract: Direct gastric mucosal cell damage mediated by nonsteroidal anti-inflammatory drugs (NSAIDs) is involved in the formation of NSAID-induced gastric lesions. We recently suggested that this direct cytotoxicity of NSAIDs is caused by their membrane-permeabilization activity. Geranylgeranylacetone (GGA), a clinically used antiulcer drug, can protect gastric mucosa against lesion formation mediated by NSAIDs. However, the mechanism by which this occurs is not fully understood. In this study, we show that GGA acts to stabilize membranes against NSAIDs. GGA suppressed NSAID-induced permeabilization of calcein-loaded liposomes and NSAID-induced stimulation of K(+)-efflux across the cytoplasmic membrane in cells. GGA was effective even when coadministered with NSAIDs and was also able to restore membrane fluidity that had been compromised by NSAIDs. This mechanism seems to play an important role in the antiulcer activity of GGA.
authors.affiliation: Graduate School of Medical and Pharmaceutical Sciences, Kumamoto University, Kumamoto 862-0973, Japan.
authors.forename: Hironori
authors.initials: H
authors.lastname: Ushijima
authors.forename: Ken-Ichiiro
authors.initials: K
authors.lastname: Tanaka
authors.forename: Miho
authors.initials: M
authors.lastname: Takeda
authors.forename: Takashi
authors.initials: T
authors.lastname: Katsu
authors.forename: Shinji
authors.initials: S
authors.lastname: Mima
authors.forename: Tohru
authors.initials: T
authors.lastname: Mizushima
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects*; D000897:Anti-Ulcer Agents / Q000494:pharmacology*; D002463:Cell Membrane Permeability / Q000187:drug effects; D004224:Diterpenes / Q000494:pharmacology*; D005454:Fluorescence Polarization; D005753:Gastric Mucosa / Q000166:cytology / Q000187:drug effects* / Q000473:pathology; D006801:Humans; D017136:Ion Transport; D008560:Membrane Fluidity / Q000187:drug effects; D011188:Potassium / Q000378:metabolism; D013276:Stomach Ulcer / Q000139:chemically induced / Q000378:metabolism / Q000517:prevention & control*; D014407:Tumor Cells, Cultured
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000897:Anti-Ulcer Agents; D004224:Diterpenes; D011188:Potassium; C031049:geranylgeranylacetone