cardiac allografts (day 7) as demonstrated by DNA fragmentation as well as TUNEL assay, whereas it was not detectable in isografts and naive controls. Double staining of the graft at the time point of graft loss showed 54 % of apoptotic cardiomyoctes and 46% of immune competentcells.Western-blot analysisrevealed complete loss of expression ofthe survivalgene Bcl-2 in rejecting allografts, in comparison to naive and isograft control hearts, whereas Bax protein level were upregulated about two-fold.A Bcl-2 cleavage product, about 17kD, could be detected, indicating posttranscriptional degra- dation ofBcl-2 as regulatory mechanism. p53 levels did notvary significantly between rejecting grafts, isograftsand naive control hearts, suggesting that p53 might not be involved at a transcriptional level in the regulation of bcl-2/bax expression. Conclusions: Thus, the induction ofapoptosisby loss of Bcl-2 activity may play an integral part in the host rejection cascade leading to acute allograft loss. Inhibiting Bcl-2 proteolysis in order to prevent apoptosis induction may provide a novel target for immunosuppres- sive therapy. 431 Does the Application of Electrical Microcurrent Heal Heart Failure? First Pre-Clinical In Vivo Results J.H. Mueller, 1 B. Kappeler, 2 M. Hofmann, 2 U.M.Losert, 2 K. Macfelda, 2 1 Berlin Heart,Berlin,Germany; 2 Medical University of Vienna,Vienna,Austria Purpose: It has been shown that unloading of hearts by mechanical cardiac assist devices leads to improvement of the heart’s function to variable extent. Improvement fails if the extracellular matrix (ECM) has been remodelled definitively. Thus, the limiting factorsfor improvement are not the myocytes but the matrix. The goal of these in-vivo experiments is to investigate the effect of electrical microcur- rent (MC) on the ECM and as a consequence on healing of heart failure. As previously published, MC is able to modify the myocardium (collagen, MMPs,TIMPs) of spontaneously hypertensive rats (SHR) under in-vitro conditions. Methodsand Materials: Two plane electrodeswere surgically placed around the heart of SHR covering the right and the left heart’s epicardium. MC was applied overa period of5 days.Thereafter, parameter of the ECM of the myocardium was analysed and compared to the myocardium from wild type rats (WKY) and SHR without previous MC application. Gene expression (quantitative PCR) was measured for MMP 2, 3, 8, 9, 13, 14, 16; TIMP 1, 2, 3, 4; connexin 40, 43, 45 and collagen I and III and eventually the level of IL-6. Results: Compared to the myocardium of WKY, the myocardium of SHR without MC application showed a significantly higher level of MMP 3,significant lower level of MMP 8,14,16 and an unchanged level of MMP 2 and 13. The TIMPs and connexinswere only marginally altered. Collagen I showed an upregulation of 40 %. After MC application, MMP 2, 3, 9, 13, 14 and 16 were signifi- cantly up-regulated, MMP 8 remained unchanged, and most impor- tantly,collagen I up-regulated by a factor of 2.5. All other analysed parameters were not altered significantly by MC application. The gene expression level of IL-6 was significantly downregulated. Conclusions: MC application regulates MMPs as well as collagen I on the gene level and normalizes the ECM of hearts in a progressed state of failure.Interestingly, the proinflammatory IL-6 was significantly downregulated. MC application initializes a process towards healing of the diseased myocardium. 432 Interplay between Coagulation and Inflammation in Lung Transplantation Ischemia-Reperfusion C.L.Lau, 1 J. Kim, 2 D.J. Pinsky, 3 1 Surgery, University of Virginia, Charlottesville, VA; 2 Surgery, University of Michigan, Ann Arbor, MI; 3 Internal Medicine, University of Michigan, Ann Arbor,MI Purpose: Ischemia-reperfusion injury continues to plague the field of lung transplantation, and this early injury has been linked to the subsequent development and severity of chronic rejection. In acute lung injury processes such as ventilator-induced injury, sepsis,or acute respiratory distress syndrome the interaction between coagula- tion and inflammation has become an increasing area of focus. This study investigates the interplay between these two cascades in ischemia-reperfusion in lung transplantation. Methods and Materials: Mice lacking the plasminogen activator inhibitor-1 gene (PAI-1; and thus have increased lysis of endogenous fibrin), mice lacking the tissue-plasminogen activator gene (tPA; and hence lessable to dissolve accrued fibrin), and wild-type mice underwent in-situ left lung ischemia and reperfusion. Fibrin deposi- tion in the lung was evaluated by immmunoblotting. Myeloperoxidase assay was used to quantitate lung tissue neutrophil accumulation. Proinflammatory mediators were measured in lung tissue, bronchoal- veolar lavage, and blood samples using enzyme-linked immunosor- bent assays. Results: Ischemia-reperfusion caused fibrin deposition in murine lungs. Less fibrin was seen in PAI-1 null mice compared to wild-type. Increased myeloperoxidase activity in the lung was seen in the tPA null mice compared to wild-type and PAI-1 null mice. Cytokine- induced monocyte chemoattractant protein-1 (MCP-1) and TNF- were increased in the tPA null mice and decreased in the PAI-1 null mice compared to the wild-type mice. Conclusions: Lung ischemia triggers a procoagulant environment with fibrin deposition in the lung. Fibrin deposition promotes inflam- mation.Preventing fibrin deposition may prevent ischemia-reperfu- sion injury and inflammation. This finding may lead to novel treatment strategiesfor ischemia-reperfusion which may help ameliorate chronic rejection. 433 The Effect of Organ-Specific CD26/Dipeptidylpeptidase IV (DPP IV) – Inhibitor – Preconditioning on Acute Pulmonary Allograft Rejection in Rats W. Jungraithmayr, 1 B. Oberreiter, 1 I. DeMeester, 2 P. Vogt, 1 M. Cardell, 1 W. Zhai, 1 S.Hillinger, 1 K. Augustyns, 2 S.Arni, 1 S.Scharpe, 2 W. Weder, 1 S.Korom, 1 1 Thoracic Surgery, University Hospital,Zurich,Switzerland; 2 Department of Pharmaceutical Sciences, University of Antwerp, Antwerpen, Belgium Purpose: The T cell activation Ag CD26/DPP IV combines costimu- latory and enzymatic properties. Its catalytic epitope functions as dipeptidyl peptidase IV (DPP IV), an exopeptidase that modulates the biological activity of chemokines/interleukins by dipeptide cleavage. Targeting systemic enzymatic activity has abrogated acute and accel- erated rejection in rat heart and lung transplantation (Tx), and local perfusion ofpulmonary graftshas reduced ischemia/reperfusion injury. We investigated the combined graft-preserving- and anti- rejection-effect of pulmonary inhibitor preconditioning on the early post-Tx phase. Methods and Materials: An allogeneic rat orthotopic single lung Tx model was employed (LBNF1 to LEW). Control lungs (I) were flushed with Perfadex ® vs. experimentalgrafts (II), perfused with Perfadex ® AB192 (diphenylphosphonate, smallmol.weight inhbi- tor) (25 mol/L) and transplanted (ischemia ⱕ 45 min). Both groups were treated with cyclosporin (CsA) at a dose of 2.5 mg/kg/day. Analysis on day 5 included pO 2 , pCO 2 and histological acute rejection (AR) grading (ISHLT). S216 Abstracts The Journal of Heart and Lung Transplantation February 2008