Insulin concentration and expression in islets. A: Effect of STZ on plasma insulin concentration in PTGS-deficient mice. Wild-type (CTRL), PTGS-1−/−, and PTGS-2−/− mice and mice receiving SC-236 were treated by a single injection of STZ (200 mg/kg BW), and on day 4, insulin concentrations were measured in plasma samples by enzyme immunosorbent assay. B: Effect of STZ on insulin expression in islets. Pancreata were isolated and cryopreserved and sections were immunostained using insulin-specific antibodies. Representative stainings are shown (n = 3; original magnification ×200). C: Insulin-immunostained islet area. After immunostaining, sections were captured digitally, and areas stained by anti-insulin antibody were determined. Data are shown as mean ± SEM; n = 5. *P < 0.05 vs. control; #P < 0.05 vs. STZ-treated CTRL.