title: Effects of Pasteurella haemolytica leukotoxin and lipopolysaccharide on histamine, prostanoid, and leukotriene release by bovine lung parenchyma in vitro.
abstract: OBJECTIVE
  To identify the effect of Pasteurella haemolytica lipopolysaccharide (LPS) and leukotoxin (LKT) on spontaneous and calcium ionophore-induced histamine and inflammatory mediator release from isolated bovine lung parenchyma.
  
  
  METHODS
  Lungs from 8 healthy cattle.
  
  
  METHODS
  Isolated bovine lung parenchyma was incubated in vitro for 2 hours with LKT or LPS, and spontaneous and induced release of inflammatory mediators was determined.
  
  
  RESULTS
  LKT and LPS increased spontaneous release of histamine and leukotriene B4. In addition, incubation with LPS increased spontaneous release of prostaglandin E2. Moreover, a differential effect of the 2 toxins on calcium ionophore-induced inflammatory mediator release was observed. LKT specifically primed isolated lung parenchyma to release leukotriene B4 and thromboxane B2 in response to calcium ionophore, whereas LPS did not alter the profile of prostanoids released by bovine lung tissue exposed to calcium ionophore.
  
  
  CONCLUSIONS
  Pasteurella haemolytica toxins have a direct effect on bovine lung parenchyma, causing release of inflammatory mediators, which contribute to response to infection. Furthermore, bacterial toxins (LKT in this study) may sensitize tissues to the effects of other irritant stimuli, amplifying the inflammatory response.
authors.affiliation: Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison 53706, USA.
authors.forename: R
authors.initials: R
authors.lastname: Saban
authors.forename: R V
authors.initials: RV
authors.lastname: Broadstone
authors.forename: M
authors.initials: M
authors.lastname: Haak-Frendscho
authors.forename: S
authors.initials: S
authors.lastname: Skoyen
authors.forename: J
authors.initials: J
authors.lastname: Fialkowski
authors.forename: S K
authors.initials: SK
authors.lastname: Maheswaran
authors.forename: D E
authors.initials: DE
authors.lastname: Bjorling
authors.forename: C
authors.initials: C
authors.lastname: Czuprynski
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000494:pharmacology*; D002417:Cattle; D015232:Dinoprostone / Q000378:metabolism; D015777:Eicosanoids / Q000378:metabolism; D005098:Exotoxins / Q000494:pharmacology*; D006632:Histamine / Q000378:metabolism; D007476:Ionophores / Q000494:pharmacology; D007975:Leukotriene B4 / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008168:Lung / Q000187:drug effects* / Q000378:metabolism; D016978:Mannheimia haemolytica; D009924:Organ Culture Techniques; D013929:Thromboxane B2 / Q000378:metabolism; D013997:Time Factors
chemical_list: D001427:Bacterial Toxins; D015777:Eicosanoids; D005098:Exotoxins; D007476:Ionophores; D008070:Lipopolysaccharides; C018579:leukotoxin; D007975:Leukotriene B4; D013929:Thromboxane B2; D006632:Histamine; D015232:Dinoprostone