title: Morphologic characteristics of pulmonary macrophages in cetaceans: particular reference to pulmonary intravascular macrophages as a newly identified type.
abstract: We examined the morphologic characteristics of pulmonary macrophages in 42 specimens of Odontoceti (Globicephala macrorhynchus, Grampus griseus, Tursiops truncatus, Stenella attenuata, Stenella coeruleoalba, Berardius bairdii), using light and electron microscopes as well as immunohistochemistry with SRA-E5. SRA-E5-positive alveolar macrophages and pulmonary interstitial macrophages contained graphitic soots, indicating the clearance of airborne, aspirated foreign bodies. Pulmonary intravascular macrophages (PIMs), positive with SRA-E5, were present within pulmonary capillaries, attaching to applied endothelial cells by cell junctions. They showed cytoplasmic tubular structures of micropinocytosis vermiformis and erythrophagocytosis, indicating their contributory role in the clearance of blood-borne particles. The uptake of pathogens by PIMs may be associated with the inducement of acute lung injury, especially bacterial infectious pneumonia. This study revealed for the first time the presence of PIMs in cetaceans.
authors.affiliation: Laboratory of Veterinary Pathology, Graduate School of Agriculture and Biological Sciences, Osaka Prefecture University, Gakuencho 1-1, Sakai, Osaka 599-8531, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kawashima
authors.forename: M
authors.initials: M
authors.lastname: Kuwamura
authors.forename: M
authors.initials: M
authors.lastname: Takeya
authors.forename: J
authors.initials: J
authors.lastname: Yamate
mesh_terms: D000818:Animals; D004289:Dolphins / Q000033:anatomy & histology*; D005260:Female; D008168:Lung / Q000098:blood supply / Q000166:cytology* / Q000648:ultrastructure; D008264:Macrophages / Q000166:cytology* / Q000648:ultrastructure; D016676:Macrophages, Alveolar / Q000166:cytology* / Q000648:ultrastructure; D008297:Male; D013194:Staining and Labeling; D014907:Whales / Q000033:anatomy & histology*