TRANSCRIPTION AND TRANSLATION OF INDUCIBLE NITRIC-OXIDE SYNTHASE IN THE PANCREAS OF PREDIABETIC BB RATS

The inducible NO synthase (iNOS) was found to be expressed in pancreat ic lesions of adult diabetes-prone BB rats. Pancreatic iNOS mRNA was d etected by reverse transcriptase PCR in pancreatic RNA of adult diabet es-prone BB rats but not in normal Wistar rats, young diabetes-prone B B rats without insulitis or in diabetes-resistant BB rats. Immunohisto chemistry of pancreatic sections using an iNOS-specific antiserum labe led the pancreas of adult diabetes-prone BB rats but not Wistar rats. Parallel staining for ED1-positive macrophages showed restriction of i NOS expression to areas of islet infiltration by macrophages. In concl usion, the data provide direct evidence for enhanced expression of ind ucible NO synthase in tissue lesions during the development of autoimm une diabetes.