DIFFERENT TOXIC EFFECTS OF HYDROGEN-PEROXIDE, NITRIC-OXIDE, AND SUPEROXIDE ON HUMAN, PIG, AND RAT ISLETS OF LANGERHANS

Susceptibility of islet cells to damage by hydrogen peroxide, superoxi de, and nitric oxide was determined on islets isolated from humans, pi gs, and rats. Islets were incubated for 20 hr at 37 degrees C with dif ferent concentrations of hydrogen peroxide, hypoxanthine/xanthine oxid ase, or nitroprusside sodium, respectively. Islet cell damage was then measured as trypan blue-uptake. Rat islets showed a higher sensitivit y than human or pig islets to damage by reactive oxygen species or nit ric oxide. These results indicate that pig islets may be a more suitab le model than rat islets to study inflammatory islet cell damage in di abetes and clinical islet transplantation.