title: Oxidative response of neutrophils to platelet-activating factor is altered during acute ruminal acidosis induced by oligofructose in heifers.
abstract: Reactive oxygen species (ROS) production is one of the main mechanisms used to kill microbes during innate immune response. D-lactic acid, which is augmented during acute ruminal acidosis, reduces platelet activating factor (PAF)-induced ROS production and L-selectin shedding in bovine neutrophils in vitro. This study was conducted to investigate whether acute ruminal acidosis induced by acute oligofructose overload in heifers interferes with ROS production and L-selectin shedding in blood neutrophils. Blood neutrophils and plasma were obtained by jugular venipuncture, while ruminal samples were collected using rumenocentesis. Lactic acid from plasma and ruminal samples was measured by HPLC. PAF-induced ROS production and L-selectin shedding were measured in vitro in bovine neutrophils by a luminol chemiluminescence assay and flow cytometry, respectively. A significant increase in ruminal and plasma lactic acid was recorded in these animals. Specifically, a decrease in PAF-induced ROS production was observed 8 h after oligofructose overload, and this was sustained until 48 h post oligofructose overload. A reduction in PAF-induced L-selectin shedding was observed at 16 h and 32 h post oligofructose overload. Overall, the results indicated that neutrophil PAF responses were altered in heifers with ruminal acidosis, suggesting a potential dysfunction of the innate immune response.
authors.affiliation: Laboratory of Inflammation Pharmacology, Institute of Pharmacology and Morphophysiology, Faculty of Veterinary Science, Austral University of Chile, Valdivia 5110566, Chile. ; Master Science Program in Animal Health, Faculty of Veterinary Science, Austral University of Chile, Valdivia 5110566, Chile.
authors.forename: Claudia
authors.initials: C
authors.lastname: Concha
authors.affiliation: Laboratory of Inflammation Pharmacology, Institute of Pharmacology and Morphophysiology, Faculty of Veterinary Science, Austral University of Chile, Valdivia 5110566, Chile.
authors.forename: María Daniella
authors.initials: MD
authors.lastname: Carretta
authors.affiliation: Laboratory of Inflammation Pharmacology, Institute of Pharmacology and Morphophysiology, Faculty of Veterinary Science, Austral University of Chile, Valdivia 5110566, Chile.
authors.forename: Pablo
authors.initials: P
authors.lastname: Alarcón
authors.affiliation: Laboratory of Inflammation Pharmacology, Institute of Pharmacology and Morphophysiology, Faculty of Veterinary Science, Austral University of Chile, Valdivia 5110566, Chile.
authors.forename: Ivan
authors.initials: I
authors.lastname: Conejeros
authors.affiliation: Laboratory of Inflammation Pharmacology, Institute of Pharmacology and Morphophysiology, Faculty of Veterinary Science, Austral University of Chile, Valdivia 5110566, Chile.
authors.forename: Diego
authors.initials: D
authors.lastname: Gallardo
authors.affiliation: Laboratory of Inflammation Pharmacology, Institute of Pharmacology and Morphophysiology, Faculty of Veterinary Science, Austral University of Chile, Valdivia 5110566, Chile.
authors.forename: Alejandra Isabel
authors.initials: AI
authors.lastname: Hidalgo
authors.affiliation: Institute of Veterinary Clinical Science, Faculty of Veterinary Science, Austral University of Chile, Valdivia 5110566, Chile.
authors.forename: Nestor
authors.initials: N
authors.lastname: Tadich
authors.affiliation: Environmental Health Program, School of Public Health, Faculty of Medicine, University of Chile, Santiago 8380453, Chile.
authors.forename: Dante Daniel
authors.initials: DD
authors.lastname: Cáceres
authors.affiliation: Laboratory of Inflammation Pharmacology, Institute of Pharmacology and Morphophysiology, Faculty of Veterinary Science, Austral University of Chile, Valdivia 5110566, Chile.
authors.forename: María Angélica
authors.initials: MA
authors.lastname: Hidalgo
authors.affiliation: Laboratory of Inflammation Pharmacology, Institute of Pharmacology and Morphophysiology, Faculty of Veterinary Science, Austral University of Chile, Valdivia 5110566, Chile.
authors.forename: Rafael Agustín
authors.initials: RA
authors.lastname: Burgos
mesh_terms: D000138:Acidosis / Q000139:chemically induced / Q000276:immunology / Q000662:veterinary*; D000818:Animals; D001769:Blood; D002417:Cattle; D002418:Cattle Diseases / Q000139:chemically induced / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry / Q000662:veterinary; D007113:Immunity, Innate; D019041:L-Selectin / Q000378:metabolism; D009504:Neutrophils / Q000187:drug effects*; D009844:Oligosaccharides / Q000494:pharmacology* / Q000633:toxicity; D010972:Platelet Activating Factor / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012417:Rumen
chemical_list: D009844:Oligosaccharides; D010972:Platelet Activating Factor; D017382:Reactive Oxygen Species; C120489:oligofructose; D019041:L-Selectin
keywords: L-selectin; cow; lactic acidosis; neutrophils; reactive oxygen species