Related Experiment Video
Updated: Jul 5, 2026

Extraction of Diatom DNA from Water Samples and Tissues
Published on: November 10, 2023
Differential diagnosis between freshwater drowning and saltwater drowning based on intrapulmonary aquaporin-5
Takahito Hayashi1, Yuko Ishida, Shinya Mizunuma
1Department of Forensic Medicine, School of Medicine, Wakayama Medical University, 811-1 Kimiidera, Wakayama, 641-8509, Japan.
Abstract:
The intrapulmonary expression of aquaporin-5 (AQP5) was examined in an experimental drowning model and forensic autopsy cases to discuss the possibility for differentiation between freshwater drowning (FWD) and saltwater drowning (SWD). In animal experiments, mice were classified into four groups: (group I: FWD; group II: SWD; group III: postmortem immersion (PI); and group IV: cervical dislocation as controls. In group I, intrapulmonary AQP5 expression was significantly suppressed at both gene and protein levels, compared with the other three groups, and there was no significant difference in AQP5 expression among groups II to IV. In the next series, we examined AQP5 gene expression in human lung samples obtained from forensic autopsies at less than 48 h postmortem (nine FWD cases, five SWD cases, and 14 other cases). Although AQP5 mRNA could be detected in all lung samples under the employed experimental conditions, the intrapulmonary gene expression of AQP5 in FWD was significantly attenuated compared with the other groups. These observations imply that AQP5 expression in type I alveolar epithelial cells was suppressed by hypotonic water to prevent hemodilution from the physiological aspect. Moreover, the analysis of intrapulmonary AQP5 expression would be forensically useful for differentiation between FWD and SWD, or between FWD and PI.
More Related Videos
Related Concept Videos
Pulmonary Edema II: Pathophysiology
Aquaporins
Osmoregulation in Fishes
Cerebral Edema l: Introduction
Disorder of Water Balance
Dehydration
Dehydration occurs when the body loses fluids (particularly water).
Causes:
The major causes of dehydration include excessive sweating, fever, vomiting, diarrhea, and diuresis.
Signs and Symptoms:
Symptoms primarily include intense...
Transcellular Transport of Solutes

