Issue |
Vet. Res.
Volume 35, Number 1, January-February 2004
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Page(s) | 39 - 51 | |
DOI | https://doi.org/10.1051/vetres:2003041 | |
How to cite this article | Vet. Res. (2004) 39-51 |
DOI: 10.1051/vetres:2003041
Immunophenotypic characterization and depletion of pulmonary intravascular macrophages of horses
Om P. Parbhakara, Tanya Dukeb, Hugh G.G. Townsendc and Baljit Singhaa Departments of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, 52 Campus Drive, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada
b Small Animal Clinical Sciences, Western College of Veterinary Medicine, 52 Campus Drive, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada
c Large Animal Clinical Sciences, Western College of Veterinary Medicine, 52 Campus Drive, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada
(Received 10 February 2003; accepted 30 June 2003)
Abstract - Pulmonary intravascular macrophages (PIMs) are present in horses and are believed to increase their sensitivity to endotoxin-induced cardio-pulmonary shock. However, owing to a lack of a marker for PIMs and the inability to isolate them, their precise contributions in the horse remain unknown. We designed this study to identify an immuno-phenotypic marker for PIMs and to develop a protocol for their transient depletion with gadolinium chloride (GC). GC is a lanthanide that has been used to deplete liver and lung macrophages. The horses (N = 15) were divided into control (n = 5) and GC-treated (n = 10) groups and the lung samples were examined by routine and immunocytochemical light and electron microscopy. GC-treated horses were euthanized at 48 h (n = 6) and 72 h (n = 4) post-treatment. The PIMs reacted with MAC-387 but not with ED-1 and CD-68 anti-macrophage antibodies. GC reduced the number of PIMs in horses at 48 and 72 h compared with the control (p < 0.05). There were increased intravascular TUNEL-positive cells in GC-treated horses and electron microscopy showed apoptotic PIMs in these horses. These data show that MAC-387 is a reliable marker for PIMs and GC is a safe tool to reduce the number of PIMs.
Key words: PIMs / gadolinium / MAC-387 / apoptosis / immunohistology / immuno-electron microscopy / TUNEL
© INRA, EDP Sciences 2004