The transmural potential difference (tmpd) of the bronchial mucosa in children with chronic nonspecific respiratory diseases (CF- and non-CF-children).

In 49 children with chronic nonspecific respiratory diseases (CNSRD) of them 6 with Cystic Fibrosis (CF), 18 with extrinsic bronchial asthma and 25 children with relapsing or chronic bronchitis, the tmpd were measured in the tracheobronchial system (bronchoscopy under general anaesthesia). The tmpd differed statistically highly significant (p less than 0.001). In asthmatics with significant eosinophilia in the bronchial secretions of the main bronchus we found a tmpd of 26.2 (+/- 9.2) mV, in bronchitics of 18.7 (+/- 6.2) mV and in CF-children receiving routinely N-acetylcysteine 6.1 (+/- 1.8) mV. Since the local application of this drug produced an additional immediate decrease of the tmpd in CF-children this suggests that such drugs, the presence or absence of eosinophils in the secretions, the products of intermediate cell metabolism or the different pathogenic process could be responsible for the varying values of the tmpd in the respiratory tract.