Bronchiolar pathology. IV. a morphometric analysis of the incidence and location of lesions induced in rabbits by intratracheally injected detergent solutions.

An experimental model of bronchiolar lesions was elaborated. It consisted of three intratracheal administrations in rabbits of 2 ml of a 3 per cent detergent solution, pH 2.5-3; the adequate development of the process was induced when the second injection was given 48 h after the first and the third on days 5-6. The induced process evolved during three phases: a) hypertrophy with hyperfunction of Clara cells, cell beheading by apo- and merocrinia and denudation of basement membranes; b) lesions of subepithelial components, mainly of capillaries, with granulative response and restructuration of the peribronchiolar tissue, and c) tardy regenerative response of epithelial cells, sometimes with neoformation of bronchioli. The morphometric analysis of this experimental process asserted the validity of the model which led to damages involving at less 70 per cent of the bronchioli (under 200 epithelial nuclei on a circumferential section) and of the small bronchi (with 200-500 epithelia nuclei); the other small and large bronchi were never involved. The morphometric analysis also showed the relations of the intervals between injections to the lesional intensity and stereotyping.