title: Interactions of oxidatively modified calf skin collagen with platelets and phagocytes.
abstract: OBJECTIVE
  The effects of non-modified and oxidatively modified calf skin collagen type I on platelet aggregation and the oxidative burst of phagocytes were examined in the framework of a general hypothesis that collagen, platelets and phagocytes cooperate to modulate the oxidative burst of phagocytes and the extent of oxidative stress.
  
  
  METHODS
  Calf skin collagen type I was subjected to oxidative modification by hydrogen peroxide or hydroxyl radical. Thermal denaturation of collagen was performed in a spectrophotometer equipped with a temperature gradient device. The aggregation of isolated human platelets obtained after differential centrifugation was measured using a dual-channel aggregometer. The production of reactive oxygen species by human whole blood phagocytes was evaluated by luminol-enhanced chemiluminescence.
  
  
  RESULTS
  Oxidative modification of collagen samples was characterized by a decrease in denaturation transition temperature. Oxidatively modified samples showed a modified SDS-PAGE pattern, evidencing a significant destruction of the collagen. All oxidatively modified collagen samples, independent of the oxidation treatment applied, lost their platelet-aggregating and phagocyte oxidative burst-inducing activity.
  
  
  CONCLUSIONS
  The results suggest that reactive oxygen species were able to modify collagen. On the other hand, oxidatively modified collagen lost its activating properties towards platelets and phagocytes.
authors.affiliation: Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic. milanciz@ibp.cz.
authors.forename: Milan
authors.initials: M
authors.lastname: Ciz
authors.forename: Hana
authors.initials: H
authors.lastname: Cizova
authors.forename: Katerina
authors.initials: K
authors.lastname: Pejchalova
authors.forename: Viera
authors.initials: V
authors.lastname: Jancinova
authors.forename: Ivan
authors.initials: I
authors.lastname: Goshev
authors.forename: Boryana
authors.initials: B
authors.lastname: Mihaylova
authors.forename: Radomir
authors.initials: R
authors.lastname: Nosal
authors.forename: Antonin
authors.initials: A
authors.lastname: Lojek
mesh_terms: D000042:Absorption; D000818:Animals; D002417:Cattle; D002498:Centrifugation; D024042:Collagen Type I / Q000737:chemistry* / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D017665:Hydroxyl Radical / Q000737:chemistry; D049449:Luminescence; D010084:Oxidation-Reduction; D010586:Phagocytes / Q000378:metabolism*; D010974:Platelet Aggregation; D011489:Protein Denaturation; D017382:Reactive Oxygen Species / Q000378:metabolism; D016897:Respiratory Burst; D012867:Skin; D013053:Spectrophotometry; D013696:Temperature
chemical_list: D024042:Collagen Type I; D017382:Reactive Oxygen Species; D017665:Hydroxyl Radical; D006861:Hydrogen Peroxide