Human Nasal Epithelium: Characterization and Effects of in Vitro Exposure to Sulfur Dioxide

Abstract

Human nasal turbinate tissue from surgical specimens was dissected free of connective tissue, and primary epithelial cultures were established by explant techniques. Transmission electron microscopy revealed that cultured cells retained homogeneous cy-toplasmic granules, tonofilaments, and desmosomes and formed a homogeneous mono-layer. The epithelial cells stained positively with cytokeratin antibodies AE1, AE3, and 35BH11 but failed to stain with two other cytokeratin antibodies, AE2 and 34BE12. Staining was also positive with anti-desmoplakin I and II but negative with anti-vimentin (43BE8), anti-desmin, and anti-human factor VIII antibodies. Cultured cells were exposed to filtered air or sulfur dioxide at 1-5 ppm for 30-60 min. Although there was no increase in cell lysis as measured by chromium-51 release, SO₂ exposure significantly inhibited [³H]leucine incorporation compared to air exposure. This effect was dependent on both SO₂ concentration and exposure duration. Control experiments revealed that these SO₂ effects were not caused by the [H⁺] load produced by SO₂ exposure. Electron microscopy of cells exposed to air or SO₂ did not show any significant morphological differences.