TY - JOUR TI - Preclinical pulmonary capillary endothelial dysfunction is present in brain dead subjects AU - Glynos, Constantinos AU - Athanasiou, Chariclea AU - Kotanidou, Anastasia AU - and Korovesi, Ioanna AU - Kaziani, Katerina AU - Livaditi, Olga and AU - Dimopoulou, Ioanna AU - Maniatis, Nikolaos A. AU - Tsangaris, Iraklis and AU - Roussos, Charis AU - Armaganidis, Apostolos AU - Orfanos, Stylianos E. JO - Pulmonary Circulation PY - 2013 VL - 3 TODO - 2 SP - 419-425 PB - SAGE Publications Inc. SN - 2045-8932, 2045-8940 TODO - 10.4103/2045-8932.113189 TODO - angiotensin converting enzyme; brain death; pulmonary endothelium TODO - Pulmonary endothelium is a major metabolic organ affecting pulmonary and systemic vascular homeostasis. Brain death (BD)-induced physiologic and metabolic derangements in donors’ lungs, in the absence of overt lung pathology, may cause pulmonary dysfunction and compromise post-transplant graft function. To explore the impact of BD on pulmonary endothelium, we estimated pulmonary capillary endothelium-bound (PCEB)-angiotensin converting enzyme (ACE) activity, a direct and quantifiable index of pulmonary endothelial function, in eight brain-dead patients and ten brain-injured mechanically ventilated controls. No subject suffered from acute lung injury or any other overt lung pathology. Applying indicator-dilution type techniques, we measured single-pass transpulmonary percent metabolism (%M) and hydrolysis (v) of the synthetic, biologically inactive, and highly specific for ACE substrate H-3-benzoyl-Phe-Ala-Pro, under first order reaction conditions, and calculated lung functional capillary surface area (FCSA). Substrate % M (35 +/- 6.8%) and v (0.49 +/- 0.13) in BD patients were decreased as compared to controls (55.9 +/- 4.9, P = 0.033 and 0.9 +/- 0.15, P = 0.033, respectively), denoting decreased pulmonary endothelial enzyme activity at the capillary level; FCSA, a reflection of endothelial enzyme activity per vascular bed, was also decreased (BD patients: 1,563 +/- 562 mL/min vs 4,235 +/- 559 in controls; P = 0.003). We conclude that BD is associated with subtle pulmonary endothelial injury, expressed by decreased PCEB-ACE activity. The applied indicator-dilution type technique provides direct and quantifiable indices of pulmonary endothelial function at the bedside that may reveal the existence of preclinical lung pathology in potential lung donors. ER -