FIG. 7.

Susceptibility of PARG^Δ2-3/Δ2-3 mice to streptozotocin-induced diabetes. (A) Analysis of blood glucose levels in wild-type and PARG^Δ2-3/Δ2-3 mice after streptozotocin treatment. Five males and five females of the PARG^Δ2-3/Δ2-3 background and wild-type mice at 7 to 8 weeks of age received a single dose of streptozotocin (160 mg/kg of body weight) at day 0 or a corresponding volume of sodium citrate buffer alone (sham). Data represent mean ± standard errors of glucose concentrations in blood for all mice in each group. (B) Histological and immunohistochemical staining of pancreatic sections from mice sacrificed 10 days after treatment with streptozotocin. Note fewer insulin-positive cells in the pancreas of streptozotocin-treated PARG^Δ2-3/Δ2-3 mice, indicative of β-cell loss. Magnification, ×20. (C) Analysis of NAD⁺ levels in islet cells after treatment with streptozotocin (STZ) (2 mM) for 30 min. Each bar represents the mean value of two different experiments (± standard deviation). In each experiment, both the untreated (n = 50) and treated (n = 50) islets were obtained from the same collagenase-digested pancreas.