[Ultrastructural pathology of the alveolar apparatus in experimental drowning].

Investigations were carried out on anaesthetized rats which by a tracheotomy tube actively aspirated liquids of different osmolarities covering a range from tap water to 2.9% NaCl solution. In every range of osmolarity, the ultrastructural alterations show areolar limitations and different stages of development. In freshwater the influx of liquid causes a hypoxemic-dysoric alveolose with diffuse of pulvinate oedematous swellings of all compartments of the blood-gas-barrier, cytolysis, karyolysis, membrane desintegration, hydropic alterations of the (cell) organelles, dilatation of the drainage tracts of the alveolar interstitium. Vesicular transformation caused by a dilatation of the pinocytotic system ending in endothelial and epithelial vesiculation. Salt-water drowning leads to a hypoxemic alveolose with a marked compaction of the matrix. The epithelium shows many alterations of the surface, numerous protrusions, constrictions and expose of the basement membrane (villous transformation). Erythrocyte sludge and thorn-apple-shaped erythrocytes are found in the capillaries. Application of electron microscopy in the diagnosis of drowning allows a more reliable classification and, correspondingly, decisive improvements of the reliability of lightmicroscopical findings.