title: Comparison of superoxide production, protein kinase C and tyrosine kinase activities in neutrophils from neonatal calves and cows.
abstract: Superoxide (O2) production and intracellular signal transduction of neutrophils were evaluated in five Holstein dairy calves and five lactating cows. Opsonised zymosan (OPZ)-induced O2 production by neutrophils from neonatal calves was significantly higher (P<0.01) than that of neutrophils of cows, whereas heat-aggregated IgG (H-agg.IgG)- and phorbol myristate acetate (PMA)-induced O2 production of neutrophils were significantly lower (P< or =0.01) than those of cows. To clarify the functional differences of intracellular signal transduction in neutrophils between neonatal calves and cows, the activities of protein kinase C (PKC) and tyrosine phosphorylation were evaluated in OPZ-, H-agg.IgG- and PMA-stimulated neutrophils. Membrane-associated PKC activity of OPZ-stimulated neutrophils from neonatal calves was significantly higher (P<0.05) than that of cows, whereas PKC activity in membrane-associated fractions of H-agg.IgG-stimulated neutrophils from neonatal calves was significantly lower (P<0.05) than that of cows. A significant difference was not found in membrane-associated PKC activity of neutrophils stimulated with PMA between neonatal calves and cows. The amount of tyrosine phosphorylated 100 kDa protein in neutrophils from neonatal calves stimulated with OPZ, H-agg.IgG and PMA were 192.6, 67.8 and 97.2 per cent of those of cows, respectively. These results indicate that complement receptor type 3 (CR3)- and Fc receptor (FcR)-mediated O2 producing activities of neutrophils are clearly different between neonatal calves and cows. This phenomenon may be associated with the age-related changes in intracellular signal transduction of neutrophils including PKC activity and tyrosine phosphorylation of cellular protein.
authors.affiliation: Department of Animal Health, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Higuchi
authors.forename: H
authors.initials: H
authors.lastname: Nagahata
mesh_terms: D000375:Aging / Q000097:blood*; D000818:Animals; D000831:Animals, Newborn; D002417:Cattle; D005260:Female; D007074:Immunoglobulin G / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D013347:Subcellular Fractions / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D007074:Immunoglobulin G; D013481:Superoxides; D019000:Phosphotyrosine; D011505:Protein-Tyrosine Kinases; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate