Effects of formaldehyde on bronchial ion transport

The functions of the epithelium that lines mammalian airways are potential targets for the toxic effects of reactive chemicals such as formaldehyde. We examined the effects of formaldehyde on bioelectric properties and ion permeation of excised canine and human bronchial epithelium. Concentration-dependent reductions in short-circuit current were induced in both tissues. Sodium absorption and transcellular chloride fluxes across canine bronchial epithelium were inhibited by 65 and 35%, respectively, by 10(-3) M formaldehyde. The QO2 of isolated dog bronchial epithelial cells was reduced by 32% by 10(-3) M formaldehyde. These results are consistent with an action of formaldehyde on cellular ion permeability but effects secondary to metabolic inhibition cannot be dismissed.