[Role of the endothelium in adult respiratory distress syndrome (ARDS): the present and future].

Various morphological studies indicate that the microcirculation plays a vital role in the development of ARDS. The significance of the structural and functional integrity of the endothelium for normal pulmonary function is supported by cell biological data. Biochemical studies in bronchoalveolar lavage and blood from ARDS-patients, coupled with studies in animals and endothelial cell cultures support the role of a variety of mediators such as complement factors, products of the coagulation cascade and fibrinolytic system, enzymes, endotoxins and metabolites of arachidonic acid. Of particular importance is the interaction between neutrophilic granulocytes and the endothelium, although the individual components of this interaction and the relationship between cellular and humoral factors remain unclear. Furthermore, the literature shows that it is still uncertain, how the data obtained from studies in vivo and in vitro can be applied to ARDS in humans. Future research in this field must come to terms with the cell biology and pathobiology of the pulmonary endothelium, a hitherto neglected aspect. In addition, studies are essential to investigate possible additive or synergistic effects of mediators on inflammatory and endothelial cells. Finally, the role of more recently discovered inflammatory mediators and modulators in the pathogenesis of ARDS requires clarification.