ObjectiveTo observe the changes of expression of aquaporin-1(AQP-1)and AQP-4 in drowned and postmortem immersed rats’lungs.MethodsThirty healthy male Wistar rats were randomly divided into drowning group, postmortem immersion group and cervical dislocation group. The morpho-logical changes of rats’lungs were observed using HE staining. The mRNA and protein expressions of AQP-1 and AQP-4 in rats’lungs were detected by real-time PCR, immunohistochemistry and Western blotting, respectively.ResultsThe results of immunohistochemistry and the Western blotting showed that the protein expression of AQP-1 of the drowning group was higher than the postmortem immersion group and the cervical dislocation group(P<0.05). The result of immunohistochemistry showed that the protein expression of AQP-4 of the drowning group was higher than the postmortem immersion group and the cervical dislocation group(P<0.05)while no difference were detected among the three of them by Western blotting(P>0.05). The mRNA expressions of AQP-1 and AQP-4 in rats’lungs of the drown-ing group was significantly higher than the postmortem immersion group(P<0.05).ConclusionThe in-crease of mRNA and protein expressions of AQP-1 and AQP-4 in lungs of rats with cute lung injury of the drowning group would be useful for differentiating vital drowning from postmortem immersion.