Reaction of the respiratory tract epithelium to bronchoalveolar lavage

: The authors investigated experimentally the reaction of the airway epithelium to the bronchoalveolar lavage. The epithelium of the rabbit trachea was examined immediately after rinsing with saline and 2, 24, 48 and 72 hours after rinsing. Lavage causes excessive stimulation of goblet cells. Immediately after lavage we find in the epithelium 99% goblet cells which after releasing the secretion degenerate and are gradually expelled from the epithelium. Regeneration of goblet cells begins 24 hours after lavage and is associated with massive differentiation of new goblet cells which leads to hyperplasia of mucus secreting elements and the formation of endoepithelial mucous glands. Signs of pathological alteration of ciliated cells are most marked 2 hours after impairs subsequently the degree of alteration of these cells declines gradually. Bronchoalveolar lavage reduces markedly the ciliary border above the epithelium, the number of kinocilia declines on average to 1.5/microns 2. In the subsequent stages the number of kinocilia increases again to 7.5/microns 2. This value is still significantly lower (p less than 0.005) than in controls. In the impaired ciliary border as a morphological sign of the impaired self-cleaning ability of the airway epithelium, numerous bacteria and condensed mucus are founded. Signs of local disorders of mucus flow are apparent still three days after bronchoalveolar lavage.