Histochemical study of dipeptidylpeptidase IV in the nasal cavity organs of laboratory rodents and man.

The localization of dipeptidylpeptidase IV (DPP IV) activity was studied at light microscope level in the mucosa, glands and capillary endothelium of the human foetuses and rat, mouse and guinea pig in some prenatal and postnatal terms. Alkaline phosphatase reaction was used for complete histochemical demonstration of capillary endothelium. The two enzymes were mapped by Lojda's methods (12). The study brings knowledge of the localization of DPP IV activity in the nasal cavity structures and gives a different time survey of the onset of DPP IV activity during ontogenesis. Considering this activity we can presume that this membrane-bound protease DPP IV may participate in the metabolism of neuropeptides in the nasal cavity and play some role in immunological disturbances of patients with rhinitis.