A 63-year-old man becomes febrile and begins expectorating large amounts of mucopurulent sputum. Sputum cultures are positive for Gram-positive diplococci. Which of the following mediators of inflammation provides potent chemotactic factors for the directed migration of inflammatory cells into the alveolar air spaces of this patient?: (A) Bradykinin, (B) Histamine, (C) Myeloperoxidase, (D) N-formylated peptides
Answer is D. Chemotactic factors are substance that stimulalte cellular migration The most potent chemotactic factors for leukocytes at the site of injury are:- Complement proteins (e.g., C5a) Bacterial and mitochondrial products, paicularly low molecular weight N-formylated peptides Products of arachidonic acid metabolism (especially LTB4) -Plasmin is a fibrinolytic enzyme generated by activated Hageman factor (clotting factor XII).