The stimulatory action of tolbutamide on Ca2+-dependent exocytosis in pancreatic beta cells is mediated by a 65-kDa mdr-like P-glycoprotein.

Journal article

Intracellular application of the sulfonylurea tolbutamide during whole-cell patch-clamp recordings stimulated exocytosis >5-fold when applied at a cytoplasmic Ca2+ concentration of 0.17 microM. This effect was not detectable in the complete absence of cytoplasmic Ca2+ and when exocytosis was elicited by guanosine 5'-O-(3-thiotriphosphate) (GTPgammaS). The stimulatory action could be antagonized by the sulfonamide diazoxide, by the Cl--channel blocker 4,4'-diisothiocyanatostilbene-2,2'-disu...

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Authors: Barg, S; Renström, E; Berggren, P; Bertorello, A; Bokvist, K

• Publication status: Published
• Journal: Proceedings of the National Academy of Sciences of the United States of America
• Volume: 96
• Issue: 10
• Pages: 5539-5544
• Publication date: 1999-05-01
• DOI: 10.1073/pnas.96.10.5539
• EISSN: 1091-6490
• ISSN: 0027-8424
• Language: English
• Keywords: Glyburide; Receptors, Drug; Diabetes Mellitus, Type 2; Drug Resistance, Multiple; Islets of Langerhans; Calcium; ATP-Binding Cassette Transporters; 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; Potassium Channels, Inwardly Rectifying; Cytoplasmic Granules; Cells, Cultured; Potassium Channels; Patch-Clamp Techniques; Animals; P-Glycoprotein; Antibodies, Monoclonal; Mice, Inbred Strains; Exocytosis; Mice; Tolbutamide