Pattern of Activin A Release in a Sheep Model of Cardiopulmonary Bypass—Preliminary Results

Background: Activin A, a member of transforming growth factor-β superfamily, has been shown to be a critical cytokine released early in the inflammatory response to endotoxaemia. Surgical interventions such as cardiopulmonary bypass (CPB) are known to induce the release of pro-inflammatory cytokines. But the pattern of activin A release in CPB has not been previously documented. A further complication is that the use of unfractionated heparin during CPB releases a number of heparin-binding growth factors, of which activin A and its binding protein, follistatin, are prime examples. The aim of our study was to define the pattern of activin A release in a sheep model of CPB.