Pasteurella haemolytica lipopolysaccharide-induced arachidonic acid release from and neutrophil adherence to bovine pulmonary artery endothelial cells.
Bovine pulmonary artery endothelial cells (BPAEC) were labeled with 3H-arachidonic acid. Exposure of the labeled BPAEC to Pasteurella haemolytica lipopolysaccharide (LPS) resulted in a time- and dose-dependent release of radioactivity. The release was inhibited by 5 mM indomethacin, but inhibition was not caused by less than or equal to 500 microM indomethacin or hydrocortisone, which suggests that the release was caused primarily by a mechanism other than cyclooxygenase or phospholipase A2 metabolism of arachidonic acid. Pasteurella haemolytica LPS also caused increased adherence of bovine neutrophils to BPAEC through independent effects on both cell types. The increased adherence was inhibited by treatment of either cell type with cycloheximide or actinomycin D prior to LPS exposure, indicating that de novo protein synthesis was required in both cell types to promote the LPS-induced adherence. Lipopolysaccharide may be an important factor in neutrophil-mediated effects in pneumonic pasteurellosis by causing increased neutrophil adherence and, thus, the vascular sequestration of neutrophils. Together, these experiments provide additional evidence for the involvement of LPS in pneumonic pasteurellosis. Moreover, they provide evidence of LPS-induced endothelial activation, which could have broad ramifications in the inflammatory and immune responses of pneumonic pasteurellosis.
Paulsen
D B
DB
Department of Veterinary Pathology, College of Veterinary Medicine, Oklahoma State University, Stillwater 74078.
Confer
A W
AW
Clinkenbeard
K D
KD
Mosier
D A
DA
D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism*; D002417:Cattle; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D008070:Lipopolysaccharides / Q000633:toxicity*; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D010325:Pasteurella; D011651:Pulmonary Artery / Q000166:cytology / Q000187:drug effects* / Q000502:physiology
D001095:Arachidonic Acids; D008070:Lipopolysaccharides; D016718:Arachidonic Acid