Comparison of nasal mucociliary clearance and retention of 3-μm microspheres in maxillary and ethmoid turbinates in beagle dogs

Radiolabeled polystyrene microspheres, 3 μm geometric diameter, were instilled simultaneously onto the maxillary and ethmoid turbinates in Beagle dogs. The retention and clearance patterns of the microspheres were followed for 30 days after instillation. Mucociliary clearance velocity during the first hour after instillation from the maxillary turbinate region was 2.5 +/- 0.7 mm/min (mean +/- SE) and 0.6 +/- 0.4 mm/min from the ethmoid turbinate region. Retention of microspheres in the turbinates at 30 days after instillation was 0.1% of the initial burden, regardless of instillation site. Radiolabel-associated microspheres were excreted via the feces, with the bulk excreted in the first few days. Autoradiographs of nasal turbinates revealed particles randomly located in the epithelial submucosa. 5 references, 3 figures, 1 table