EXTRA ISLET INFILTRATION IN NOD MOUSE PANCREAS - OBSERVATIONS AFTER IMMUNOMODULATION

This study describes the morphology, time appearance, persistence, and immunomodulation of extraislet infiltration in the nonobese diabetic (NOD) mouse pancreas. Female NOD mice were subdivided into two groups: untreated, killed at week 5 (n = 8), 10 (n = 8), or 21 (n = 8) of lif e; ganglioside treated (200 mg/kg body wt/day given from week 4 until week 21 of life, plus complete Freund's adjuvant at week 4), killed at week 10 (n = 6), 21 (n = 6), or 25 (4 weeks after the end of the gang lioside treatment; n = 6). Mononuclear elements were seen around small ductules located both in the vicinity of and far from the islets. Lar ger ducts were completely devoid of inflammation, thus evidencing that periductulitis is specific only to small ductules. Moreover, an exocr ine focal pancreatitis was seen along septa and may demonstrate that m acrophage activation takes place throughout the pancreatic connective tissue. Immunomodulation determines some suppression of insulitis; nev ertheless, after treatment withdrawal, a reinfiltration occurs both wi thin and outside the islets.