Role of intracellular calcium in Pasteurella haemolytica leukotoxin-induced bovine neutrophil leukotriene B4 production and plasma membrane damage.
Isolated neutrophils were used to study the intracellular calcium ([Ca2+]i) dependency of Pasteurella haemolytica leukotoxin-induced production of leukotriene B4 and plasma membrane damage. Exposure of neutrophils to leukotoxin caused a rapid and concentration-dependent increase in [Ca2+]i, followed by simultaneous plasma membrane damage and production of leukotriene B4. Removal of extracellular Ca2+, replacement of Ca2+ with other divalent cations, or exposure to high concentration of verapamil, an inhibitor of voltage-dependent calcium channels, inhibited leukotoxin-induced increases in [Ca2+]i, leukotriene B4 production, and membrane damage, thus indicating that influx of extracellular Ca2+ is necessary to produce these leukotoxin-induced neutrophil responses.
Cudd
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Department of Anatomy, Pathology, and Pharmacology, College of Veterinary Medicine, Oklahoma State University, Stillwater, USA. Clarke@okway.okstate.edu
Clarke
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C
Clinkenbeard
K
K
Shelton
M
M
Clinkenbeard
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P
Murphy
G
G
D000818:Animals; D001427:Bacterial Toxins / Q000494:pharmacology; D002118:Calcium / Q000502:physiology*; D002417:Cattle; D002462:Cell Membrane / Q000187:drug effects; D005098:Exotoxins / Q000494:pharmacology; D007975:Leukotriene B4 / Q000378:metabolism*; D008163:Luminescent Measurements; D016978:Mannheimia haemolytica / Q000378:metabolism*; D009504:Neutrophils / Q000187:drug effects* / Q000378:metabolism; D013997:Time Factors; D014700:Verapamil / Q000494:pharmacology
D001427:Bacterial Toxins; D005098:Exotoxins; C018579:leukotoxin; D007975:Leukotriene B4; D014700:Verapamil; D002118:Calcium