Extracellular Matrix Components of Rat Lungs after Direct and Indirect Lung Injury.

We studied the effects of direct intratracheal and indirect intravenous administration of pathogen on the concentrations of types I, III, and IV collagens and fibronectin and expression of the corresponding genes at the early stages of LPS-induced lung injury. Direct and indirect administration of LPS increased the level of type III collagen and decreased the expression of genes encoding types I and III collagens. Expression of type IV collagen remained unchanged. Considerable decrease in fibronectin gene expression was observed after direct LPS administration. Thus, changes in the extracellular matrix of the lungs at the early stages of acute lung injury differ depending on the way of pathogen administration.