Differential activation of coronary and pulmonary endothelial cells by thermal injury.

Abstract

Remote organ dysfunction during resuscitation of severe thermal injury is characterized by early, transient pulmonary insufficiency and cardiac contractile dysfunction. Thermal injury is typified by profound systemic alterations of endothelial immunological, vasoactive, and barrier functions. The unique location of this ubiquitous, fragile monolayer makes it vulnerable to circulating serum factors created at remote cutaneous wounds. We examined endothelial "activation" in 2 distinct cell types, human coronary and pulmonary endothelial cells (EC), after severe thermal injury. By using human serum isolated at specific times after thermal injury ("early" [2 h post-burn] or "late" [26 h post-burn]), the endothelial release of vasoactive mediators, ICAM-1 expression, and monolayer permeability were assessed in vitro. Early burn serum enhanced coronary EC vasoconstrictor (ET-1) release and ICAM expression, inhibited vasodilator (PGI2) release, but had no effect on permeability. Conversely, under similar conditions, pulmonary EC PGI2 release and permeability were enhanced, ET-1 release was diminished, but ICAM was unaffected. Late burn serum enhanced vasodilator (NO) release and permeability to albumin in both coronary and pulmonary EC, whereas ET-1 release was inhibited. Under these conditions, only pulmonary ICAM expression was significantly enhanced. These data suggest that human endothelium isolated from divergent vascular beds are activated by burn injury in a unique manner for time post-burn and vascular site of cell origin.