|[Frontiers in Bioscience 2, d232-241, June 1, 1997]|
THE COMPARATIVE BIOLOGY OF PULMONARY INTRAVASCULAR
Department of Surgical and Radiological Sciences, School of Veterinary Medicine University of California, Davis, CA
Received 4/11/97; Accepted 5/21/97
Pulmonary intravascular macrophages are an important
part of the mononuclear phagocyte system in some species of mammals,
mainly sheep and other ruminants, pigs, and horses. These cells
phagocytize foreign particles, cell debris and pathogens that
pass through the pulmonary circulation. Species with intravascular
macrophages localize intravenously injected tracer particles and
bacteria predominantly in the lung rather than the liver, and
exhibit pulmonary hypertension when these cells are activated.
Both in vivo and in vitro studies show that pulmonary
intravascular macrophages have distinct secretory and immune capabilities.
Consequently, the pulmonary intravascular macrophages play an
important role in pulmonary inflammation in species that have