FIG. 5.

Effect of enhancing signaling downstream of PERK/eIF2α on the changes in gene expression and insulin secretion in islets of ob/ob mice. A: Islets isolated from ob/ob and age-matched control mice were cultured in the absence (control [cont], white bars; ob/ob, black bars) or presence (ob/ob+S, striped bars) of salubrinal (75 μmol/L) for 24 h. Total RNA was extracted, reverse-transcribed, and analyzed by real-time RT-PCR. mRNA levels were expressed as fold change of the level in control islets. n = 3–6 in each group. B: Batches of islets were cultured in Krebs-Ringer HEPES buffer containing 0.1% BSA and 2.8 mmol/L (white bars) or 16.7 mmol/L glucose (black bars) for 1 h. Insulin was measured in an aliquot of the buffer by radioimmunoassay. Insulin secretion was expressed as fold change of the level in control islets cultured in 16.7 mmol/L glucose. n = 3–6 in each group. All results are mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001 genotype effect; †P < 0.05 salubrinal treatment effect in ob/ob mouse islets.