Peroxynitrite formation in the orbit of diabetics with rhinocerebral mucormycosis

Objective: To evaluate whether an intact respiratory burst exists within th e orbit of diabetics with rhinocerebral mucormycosis. Methods: Immunohistoc hemical detection of nitrotyrosine in the orbital tissue of diabetics requi ring exenteration due to rhinocerebral mucormycosis. Nitrotyrosine is the s table product of the nitration of tyrosine residues by peroxynitrite. Perox ynitrite is a potent oxidant produced by the combination of superoxide and nitric oxide during the respiratory burst. Results: Four specimens were ana lyzed. All showed focal areas of specific staining against nitrotyrosine of the walls and internal structures of fungal organisms. Conclusions: An int act respiratory burst is present in the orbit of diabetics during infection with rhinocerebral mucormycosis. Possible mechanisms of peroxynitrite's mi crobicidal effects and reasons for a deficiency in diabetics are discussed.