Adverse effects of toxins and drugs on the surfactant systems.

Various inhaled or administered compounds have adverse effects on the surfactant system. In experimental animals quartz inhalation induces alveolar proteinosis. This condition may also be induced by amphiphilic drugs or through increases in surfactant apoproteins. In one experimental model, damage to Clara cells by a methyl-furan derivative led to an increase in extracellular surfactant levels without a change in whole lung pool size. A comparative study of the effects of nitrogen dioxide in the rat and hamster demonstrated differing effects on Clara cells, type II and surfactant levels. These and other studies demonstrate that the effects of chemicals and drugs on cells involved in surfactant synthesis, secretion and catabolism provide a sensitive indicator of incipient toxic effects in the lung.