OBJECTIVE AND DESIGN:To document in vivo immunolocalization and activation of nuclear factor-kappaB (NF-kappaB) and inducible nitric oxide synthase (iNOS) expression in prediabetic stages of diabetes mellitus.
MATERIAL OR SUBJECTS:Genetic, diabetic-prone or diabetic-resistant BB rats (total = 189).
TREATMENT:Various doses of an oral dithiocarbamate derivative, NOX-700, or cyclosporine (2.5 mg/kg) starting at 30 or 60 days of age.
METHODS:Immunohistochemistry, electrophoretic mobility shift assays, plasma glucose.
RESULTS:NF-kappaB and iNOS was increased in pancreas of hyperglycemic, diabetic-prone rats but not normoglycemic, diabetic-resistant rats. Immunostaining for NF-kappaB and iNOS was largely confined to islets and occurred in diabetic-prone rats prior to overt hyperglycemia. NOX-700 decreased cell infiltration, delayed the onset of disease and decreased the incidence of hyperglycemia to levels achieved by immunosuppressant therapy. NOX-700 also decreased the intensity of immunoreactive NF-kappaB and iNOS within pancreatic islets.
CONCLUSIONS:These studies support a role of NF-kB and iNOS in diabetogenesis in vivo.