title: Islet cell metabolism is reflected by the MTT (tetrazolium) colorimetric assay.
abstract: Insulin secretion depends critically on glucose metabolism. We investigated whether a rapid viability test could be established for assessing glucose metabolism in insulin secreting cells. The MTT (C,N-diphenyl-N'-4,5-dimethyl thiazol-2-yl tetrazolium bromide) colorimetric assay (reduction of tetrazolium salt to formazan) was applied to rat islets and rat insulinoma cell lines. It was found that the rate of formazan production correlated with glucose oxidation and glucose utilization at glucose concentrations which also stimulated insulin secretion. In differentiated insulinoma INS-1 cells, salt reduction paralleled the insulin release at glucose concentrations of up to 8.3 mmol/l. The glucose-induced formazan production in INS-1 cells and islets was abolished by exposure to the Beta-cell cytotoxic agents, streptozotocin or alloxan. The MTT assay thus provides a convenient tool for the rapid assessment of Beta-cell metabolism and viability.
authors.affiliation: Laboratoires de Recherche Louis-Jeantet, Faculty of Medicine, University of Geneva, Switzerland.
authors.forename: D
authors.initials: D
authors.lastname: Janjic
authors.forename: C B
authors.initials: CB
authors.lastname: Wollheim
mesh_terms: D000496:Alloxan / Q000494:pharmacology; D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D003124:Colorimetry / Q000379:methods; D005947:Glucose / Q000378:metabolism* / Q000494:pharmacology; D007202:Indicators and Reagents; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007340:Insulinoma / Q000378:metabolism*; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D010190:Pancreatic Neoplasms / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013311:Streptozocin / Q000494:pharmacology; D013778:Tetrazolium Salts; D013844:Thiazoles
chemical_list: D007202:Indicators and Reagents; D007328:Insulin; D013778:Tetrazolium Salts; D013844:Thiazoles; D013311:Streptozocin; D000496:Alloxan; C022616:thiazolyl blue; D005947:Glucose