The metabolic amplification of insulin secretion is strongly affected by cell culture

Background and aims: Metabolic amplification of insulin secretion is still poorly understood in spite of considerable research efforts. Here, we have tested the hypothesis that at least part of the conflicting results is due to different cellular models. Methods: Freshly isolated or cultured (24 to 48h in RPMI1640) mouse islets were used to measure insulin secretion by perifusion and ELISA of the fractionated efflux. The mitochondrial redox potential was assessed by measuring islet NAD(P)H- and FAD-autofluorescence. Results: A 60 min pre-perifusion with 500µM tolbutamide in absence of nutrients virtually abolish…