Lung fat embolism in cetaceans stranded in Canary islands

Abstract

The presence in hepatocytes of intracytoplasmic inclusions has been described both in human and in veterinary medicine, being associated to different agents and pathogenic mechanisms. In cetaceans, the presence of this type of globules has been frequently described in animals stranded individual or massively. For the accomplishment of this work, samples of liver, corresponding to 108 cetaceans of 17 different species, stranded in the Canary Islands had been studied. In the cytoplasm of hepatocytes of 58 animals of 12 species, hyalines eosinophilic globules were observed, with a size between 4 and 20 μm. In 49 out of the 58 livers showing those inclusions, histochemical (Pas-diastase) and immunocytochemical (detection of alpha-1-antitrypsine) techniques were perfomed on formaline-fixed, paraffin-embedded sections. The results showed 26 positive livers to both techniques, 22 of which were associated with hepatic congestion, 10 were just PAS diastase positive, 6 only α-1-AT positive and 7 negative to both staining procedures. In the present study, the acute hepatic congestion was observed in 53% of the α-1-AT positive animals. The origin of these intracellular changes is probably related to hemodynamic phenomena suffered by the cetaceans stranded alive, in addition to hyperthermia and/or other factors wich may induce the production and storage of α-1-AT and as other acute phase proteins (under current study) in the hepatocytes.