{Reference Type}: Journal Article {Title}: Quantitative Morphological Study of Larynx APUD-Cells in Asphyxial Type of Drowning in Fresh Water (Experimental Study). {Author}: Giniatullin RU; {Journal}: Bull Exp Biol Med {Volume}: 177 {Issue}: 2 {Year}: 2024 Jun 1 {Factor}: 0.737 {DOI}: 10.1007/s10517-024-06173-1 {Abstract}: An additional microscopic diagnostic sign has been identified for verification of asphyxial type of drowning. In white non-linear male rats (age 2 months) subjected to free drowning, significant hyperplasia of argyrophilic and morphofunctional activity of serotonin-containing APUD-cells of the laryngeal mucosa were revealed under conditions of acute anoxia in comparison with the intact control. These changes promote the development of laryngospasm, which prevents water penetration into the airways and lungs in asphyxial type of drowning. The presence of statistically significant hyperplasia of argyrophilic and morphofunctional activity of serotonin-containing APUD-cells of the laryngeal mucosa under conditions of acute anoxia can be used as an additional diagnostic criterion for asphyxial type of drowning in experimental studies.