FIGURE 3.

Effects of glutamine, leucine, and succinate on insulin secretion. A, islet perifusion assay with glutamine (Gln) or glutamine + leucine (Gln+Leu) at low glucose. Each plot represents the mean of two different mice. Mice are 6 months old. Right, mean of area under the curve (AUC) calculated for the perifusion plots. B, insulin secretion in response to glucose (16.7 mm), leucine (10 mm, in the presence of 3 mm glucose), and methyl succinate (10 mm) plus α-ketoisocaproate (KIC; 2 mm) in lox/lox and βLKB islets using static incubation. Mice were 4 months old. Data represent the mean of three or four independent experiments. *, p < 0.05.