Activation of peritoneal macrophages during the prediabetic phase in low-dose streptozotocin-treated mice

Glucose metabolism and the production of O2- and NO2- have been studied in peritoneal macrophages from mice injected with 5 subdiabetogenic doses of streptozotocin. On day 12 after beginning of the treatment, peritoneal macrophages produced significantly higher amounts of lactate than macrophages from control mice. In addition, NO2- release and phorbol ester-induced O2- production were significantly augmented in macrophages from streptozotocin-treated mice. gamma-Interferon induced in a dose-dependent manner the activity of NO synthase only in macrophages from streptozotocin-treated mice. These data show for the first time that peritoneal macrophages from streptozotocin-treated mice are activated and produce effector molecules such as O2- and .NO which could participate in the destruction of pancreatic islets.