Preoperative irradiation and donor splenocyte infusion induce tolerance in lung, but not heart allografts in a minipig model – role of passenger leukocytes

respectively. Mean PA pressure was 49 11.7 mmHg and 39.8 9.8 mmHg in the PAH and D-PH groups, respectively. Median ET-1 levels were significantly different across all groups (p 0.001) with higher levels in the PAH (1.545 fmol/ml, range 0.31-100) and D-PH (1.30 fmol/ml, range 0.14-1000) groups as compared to controls (0.44 fmol/ml, range 0.02-3.88; p 0.0001 and p 0.0005, respectively). There was no significant difference in median ET-1 levels between D-PH and PAH groups (p 0.25). Conclusions: This study is the first to compare ET-1 levels in PAH, D-PH, and normal controls and suggests a role of ET-1 in the pathogenesis and perhaps treatment of D-PH.