Experimental studies on early stages of the development of pulmonary silicosis in pups

Abstract

Pulmonary silicosis was produced experimentally in pups by intratracheal injection of (250 mg/kg body weight) silica dust of particle size less than 5 μ. The development of fibrosis was extremely slow in pups. In the early periods the distribution of dust particles was chiefly confined to the alveolar sacculations of respiratory bronchioles. In later periods nodules were encountered in the vicinity of bronchioles, alveolar ducts, and blood vessels which even at 240 days were composed only of thick, compactly arranged reticulin fibers. The low fibrogenicity of silica dust in pulmonary tissue of pups has been attributed to the age factor.