Decreased wound neutrophils and indiscrete margination in the pathogenesis of wound infection.
To assess the pathogenesis of increased susceptibility to infection and septic death in a rat model, neutrophils (PMNs) in the wound, circulating PMNs, and their in vivo activity were evaluated after 30% and 60% burns. Eight hours after injury there were twice as many PMNs in the wounds of rats that sustained 30% compared with 60% burns. There was no difference between these two groups in the number of circulating PMNs at 2, 4, 6, and 8 hours after injury. In vivo evaluation of PMN response to infusion of F-Met-Leu-Phe revealed that circulating PMNs were more sensitive 4 hours after 60% burns compared with sham burns. At this time PMNs were found to be less sensitive to zymosan-activated serum infusion after 30% burns compared with sham burns. However, the PMNs in rats with 30% burns were more sensitive to this stimulus than were PMNs in rats with 60% injuries. Thus rats with greater injury, known to be more susceptible to wound infection, have fewer PMNs in their wounds 8 hours after injury. This is preceded by an increased sensitivity of PMNs in vivo to bacterial chemotactic factor and a relative increase in sensitivity to wound factors. This unusual finding implicates indiscrete margination as a factor in the pathogenesis of infection.
D000818:Animals; D001830:Body Surface Area; D001835:Body Weight; D002056:Burns / Q000097:blood / Q000150:complications / Q000503:physiopathology*; D002452:Cell Count; D002630:Chemotactic Factors / Q000494:pharmacology; D004198:Disease Susceptibility; D007958:Leukocyte Count; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000008:administration & dosage; D009504:Neutrophils / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D013530:Surgical Wound Infection / Q000097:blood / Q000209:etiology* / Q000503:physiopathology; D013997:Time Factors; D014554:Urination
D002630:Chemotactic Factors; D009240:N-Formylmethionine Leucyl-Phenylalanine