title: Extracellular acidification parallels insulin secretion in INS-1 and HIT-T15 beta-cell lines.
abstract: As an alternative to manual assays that track insulin secretion, we tested a silicon-based biosensor that allows automated monitoring of extracellular acidification. Glucose stimulation of INS-1 and HIT-T15 cells resulted in a rapid increase in extracellular acidification in a biphasic and concentration-dependent fashion much like insulin secretion (EC(50) INS-1=5 mM and HIT-T15=1 mM). This response was attenuated by verapamil (10 microM) and stimulated by administration of glybenclamide (100 nM) or KCl-induced (40 mM) depolarization. These experiments suggest that automated monitoring of extracellular pH may be a useful assay and support the relevance of linking metabolic activity to insulin secretion.
authors.affiliation: Department of Physiology, 2100 Biomedical and Physical Sciences Bldg., Michigan State University, East Lansing, MI 48824-1101, USA. luckie@msu.edu
authors.forename: Douglas B
authors.initials: DB
authors.lastname: Luckie
authors.forename: John H
authors.initials: JH
authors.lastname: Wilterding
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Maleszewski
authors.forename: Errett C
authors.initials: EC
authors.lastname: Hobbs
authors.forename: L Karl
authors.initials: LK
authors.lastname: Olson
mesh_terms: D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D005947:Glucose / Q000494:pharmacology*; D005905:Glyburide / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007004:Hypoglycemic Agents / Q000494:pharmacology; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000166:cytology*; D010179:Pancreas / Q000166:cytology; D011188:Potassium / Q000494:pharmacology; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D013997:Time Factors; D014700:Verapamil / Q000494:pharmacology
chemical_list: D002121:Calcium Channel Blockers; D007004:Hypoglycemic Agents; D007328:Insulin; D011189:Potassium Chloride; D014700:Verapamil; D005947:Glucose; D011188:Potassium; D005905:Glyburide