The intense inflammatory reaction following reperfusion of the infarcted myocardium has been implicated as a factor in extension of injury. However, this inflammatory reaction is also critical to tissue repair. The cellular responses that mediate these functions are orchestrated by sequential induction and/or release of cytokines resulting in a closely regulated cytokine cascade. This paper reviews research on these cytokine cascades, their cellular origin, and factors which control the cellular response to their presence. Factors examined include leukotaxis, phenotypic transition of leukocytes, adhesion molecule induction and the role of cytokines in tissue repair and scar formation. (C) 1998 Academic Press.