Altered expression of endothelial markers - especially adhesion molecules - is diagnostically helpful for diagnosis of ante mortal undiagnosed sepsis. Up to now it is unclear whether (1) expression of Angiotensin converting enzyme (ACE) and/or VE-cadherin (VEC) plays a comparable role, (2) whether expression intensity correlates with post mortem interval. Fifty-nine lung specimens (20 lung specimens with regular morphology from tumour lobectomies, 39 from patients who died of septic ARDS due to microbiologically proven Gram-negative sepsis) were stained with an antibody against ACE (1:80) resp. VEC (1:100). All specimens showed vessel type specific expression patterns for ACE and VEC which was dramatically reduced in sepsis. ACE staining intensity did not correlate with time between death and autopsy. VEC staining was slightly but statistically not significantly reduced with increasing time interval. Pulmonary VEC and ACE expression are reduced in septic ARDS. However, as neither ACE nor VEC expression correlates with time interval between death and post mortem, expression intensities of VEC or ACE are no reliable indices for time elapsed since death.