Uptake of BrdU in olfactory and respiratory epithelium of rabbits with experimental sinusitis.

Sinusitis was induced in six rabbits in order to evaluate its influence on the proliferation of cells in the olfactory epithelium compared with the respiratory epithelium during conservative antibiotic therapy. Then 1% ofloxacin was injected into the paranasal sinuses. Three normal rabbits were not administered any treatment and served as controls. The rabbits were sacrificed under intravenous anesthesia and the olfactory and respiratory mucosa was excised 24 hours after intravenous administration with the labeling reagent 5-bromo-2'-deoxyuridine (BrdU). The extent of cell proliferation in these tissues was estimated by immunohistochemical staining with BrdU-specific antibody. The uptake of BrdU was significantly increased (p = 0.0099) in the respiratory mucosa, but not in the olfactory mucosa. Furthermore, in olfactory epithelium, 79.2% and 16.7% of all BrdU-positive cells were olfactory and basal, respectively. Thus, turnover of epithelial cells due to sinusitis was not as accelerated in the olfactory mucosa as in the respiratory mucosa during antibiotic treatment.