RT Journal Article SR Electronic T1 Effect of blood on the activity and persistence of antigen induced inflammation in the rat air pouch. JF Annals of the Rheumatic Diseases JO Ann Rheum Dis FD BMJ Publishing Group Ltd and European League Against Rheumatism SP 485 OP 490 DO 10.1136/ard.44.7.485 VO 44 IS 7 A1 Yoshino, S A1 Blake, D R A1 Hewitt, S A1 Morris, C A1 Bacon, P A YR 1985 UL http://ard.bmj.com/content/44/7/485.abstract AB The hypothesis that haem iron derived from synovial microbleeding has a proinflammatory effect on the synovial membrane was tested by adding autologous whole blood and fractions derived from it to a naturally remitting rat air pouch model of allergic inflammation. The induction of such a subcutaneous air pouch produces a cavity lined by mesenchymal cells comparable to the synovial membrane. Autologous whole blood was found to prolong a low grade inflammatory state, this effect being attributable to a red cell component, most probably haem iron. Whole blood in the absence of an inflammatory stimulus does not have this effect, indicating that the mechanism is one of prolonging or promoting existing allergic inflammation, rather than inducing an inflammatory response.