ABSTRACT
To investigate the effect of diabetes mellitus [DM] on the olfactory mucosa, an experimental study was performed with 60 albino rats from the same colony and age. The animals were divided into two groups, consisting of 10 animals as a control group [CG] and 50 animals as a diabetic group [DG], DM was induced by intraperitoneal injection of alloxan in a dose of 210 mg/kg of body weight. Widened intercellular spaces, thining of epithelial and mucous layers desquamation, ciliary loss and neural bundles atrophy [15%] were observed in DG. These changes increased by severity of diabetes and its duration. The reported atrophy may be due to genetic factors in some animals predisposing to pathogenesis of diabetic neuropathy. More or less the changes were reported in CG except neural bundles atrophy. The changes in CG were much less severe than in DG and increased by aging. The role of DM in these changes was suggested to be acceleration and exaggeration of degenerative process of aging, disharmony of regular rhythm of replication and degeneration cycles and/or renewal of basal cells and consequently failure of renewal process of sensory cells and their axonal projections. The results of this study suggested, that olfactory dysfunction with DM is a complicated process and the integrity of olfactory mucosa represents a part of its dilemma. It was advised to do meticulous control of DM as it may improve the central and peripheral process of olfaction. Also, it was concluded that the olfactory dysfunction in diabetics is still a fertile area for further studies