[Lung alterations after paraquat poisoning (author's transl)]

After one application of paraquat (35 mg/kg body weight) studies of the changes in lung structure in phospholipid content of the alveolar wash as well as in the static pV-curves are performed on adult hooded rats. Pathomorphologically 2, 4, 8, 16, 24 and 48 h after the paraquat intoxication focal atelectases, circumscribed inflammatory infiltrations of the interstitium are predominant as well as an accumulation of macrophages in the interstitium and in the alveolar space. Initially granulocytes dominate in the inflammatory infiltrates; after 8 h lymphoid elements and histiocytes became more and more apparent. 24 an 48 h after the paraquat injection there is a degradation of the alveolar epithelium. After 8-48 h the phospholipid content of the alveolar wash and after 2-48 h the hysteresis loop of the pV-curves are statistically significantly decreased in comparison with control animals. It is assumed, that the paraquat mediated dearrangement of the surfactant system of the lung is caused by an increased degradation in consequence of liberated phospholipases as well as by a decreased or ceased synthesis of the surfactant. The latter may be the consequence of an autooxydative membrane alteration of the endoplasmatic reticulum, the toxic action of the hydrogen peroxide originated by the autooxydation but also of the loss of energy rich substrates.