The effect of indomethacin on the response of bronchial epithelium to tobacco smoke.

Abstract

The effect of the anti-inflammatory agent indomethacin on the response of bronchial epithelium to irritation by tobacco smoke has been studied using the specific pathogen free rat as an experimental animal model of bronchitis. Rats given tobacco smoke alone for 2 weeks (25 digaretts during a 4-hr period on each day) showed a marked increase in their epithelial mucous (i. e. goblet) cell numbers in the trachea and at each of the four airway levels of the lung studied. Indomethacin was given by intra-peritoneal injection alone or concurrently with the tobacco smoke at a dose of 2 or 4 mg/kg/bw. When compared with their respective controls, those animals given indomethacin together with the tobacco smoke had significantly fewer mucous cells in their intrapulmonary airway (i.e. inhibition of mucous cell hyperplasia) but there was little inhibitory effect in the trachea. The inhibition of mucous cell hyperplasia afforded by indomethacin was greatest in those animals given the highest dose: the percentage inhibition ranged from 18 per cent to 100 per cent and the greatest effect was seen in the most distal intrapulmonary airways studied. The mechanism of action of Indomethacin and the role of prostaglandin is discussed.