title: Protonophoretic activity of hypoglycemic sulfonylureas in black lipid membranes.
abstract: The ability of glibenclamide and of gliclazide to act as protonophores has been studied in black lipid membranes made of glycerol monoleate as a function of pH and drug concentration. Protons may effectively be transported across lipid membranes with a maximum at a pH close to the pKa of the sulfamide (pKa of glibenclamide = 5.4). It is suggested therefore that hypoglycemic sulfonylureas may act in part as Ca2+ inward and H+ outward ionophores through plasma membranes of pancreatic B cells.
mesh_terms: D001692:Biological Transport / Q000187:drug effects; D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D005907:Gliclazide / Q000494:pharmacology; D005905:Glyburide / Q000494:pharmacology; D005990:Glycerol / Q000032:analysis; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D066298:In Vitro Techniques; D007476:Ionophores / Q000494:pharmacology; D008563:Membrane Lipids / Q000378:metabolism*; D008567:Membranes, Artificial; D011522:Protons; D013453:Sulfonylurea Compounds / Q000494:pharmacology*
chemical_list: D007004:Hypoglycemic Agents; D007476:Ionophores; D008563:Membrane Lipids; D008567:Membranes, Artificial; D011522:Protons; D013453:Sulfonylurea Compounds; D005907:Gliclazide; D005990:Glycerol; D005905:Glyburide; D002118:Calcium