Acute effects of inhalable particles on the frog palate mucociliary epithelium

This work was designed to evaluate the toxicity of inhalable particles less than or equal to 10 pm in aerodynamic diameter (PM10) collected from the urban air in São Paulo, Brazil, to the mucociliary apparatus using the frog palate preparation. Seven groups of frog palates were immersed in different concentrations of PM10 diluted in Ringer's solution during 120 min: 0 (control, n = 31); 50 (n = 10); 100 (n = 9); 500 (n = 28); 1,000 (n = 10); 5,000 (n = 11); and 10,000 mu g/m(3) (n = 10). Mucociliary transport and transepithelial potential difference were determined at 0, 30, 60, and 120 min exposure. Additional groups (control and 500 pg/m(3)) were studied by means of morphometric analyses (quantification of the amount of intraepithelial and surface mucins), measurement of cilia beat frequency, and quantification of total glutathione. Mucociliary transport and transepithelial potential difference were significantly decreased at higher concentrations of PM10 (p = 0.03 and p = 0.02, respectively). Exposure to PM10 also elicited a significant decrease of total glutathione (p = 0.003) and depletion of neutral intraepithelial mucins (p = 0.0461). These results show that PM10 can promote significant alterations in ciliated epithelium in vitro.Univ São Paulo, Sch Med, Fac Med, Lab Poluicao Atmosfer Expt, BR-01246903 São Paulo, BrazilHC FMUSP, Inst Coracao, São Paulo, BrazilUSP, Dept Bioquim, Inst Quim, BR-09500900 São Paulo, BrazilUSP, Inst Fis, Grp Estudos Poluicao Ar, BR-09500900 São Paulo, BrazilUniv Alberta, Dept Med, Pulm Res Grp, Edmonton, AB, CanadaUNIFESP, Ctr Estudios Envelhecimento, São Paulo, BrazilUNIFESP, Ctr Estudios Envelhecimento, São Paulo, BrazilWeb of Scienc