Influx of calcium is an essential but insufficient signal in sustained nutrient-stimulated insulin
secretion, and increased metabolic rate of the beta cell is also required. The aim of the study
was to test the hypothesis that the reduced state of cytochrome c is a metabolic co-factor
necessary for insulin secretion, over and above its participation in the ATP-generating
function of electron transport/oxidative phosphorylation. We found that nutrient stimulation of
insulin secretion by isolated rat islets was strongly correlated with reduced cytochrome c …