title: Experimental Study on the In-Vivo Heterotopic Transplantation of Aortic Valved Homografts after De-Endothelialization.
abstract: BACKGROUND AND AIM OF THE STUDY: The study aims were to monitor the changes in tissue morphology, calcium content and CD40 expression in the in-vivo heterotopic transplantation of aortic valved homografts after de-endothelialization, and to seek better methods for preventing calcification and degeneration of the homograft valves.
  
  METHODS: Adult, healthy, inbred male Chinese rabbits were used as donors, and inbred adult female New Zealand White rabbits as recipients for the heterotopic transplantation of aortic valved homografts with abdominal aorta. Controls received aortic valved homografts without treatment, while the de-endothelialization group received aortic valved homografts after de-endothelialization. For the cryopreservation group, aortic valved homografts were treated with 10% dimethyl sulfoxide and cryopreserved in liquid nitrogen for 60 days. Recipients were randomly allocated to three groups (n = 20 per group). Grafts were removed after two, four, eight and 12 weeks of surgery and observed with light microscopy. Calcium concentrations were monitored using flame atomic absorption, and CD40 expressions with immunohistochemistry.
  
  RESULTS: At two weeks after transplantation, the calcium contents of the fresh, de-endothelialization and cryopreservation groups were similar (p >0.05). The calcium content at four, eight and 12 weeks in the fresh and cryopreservation groups was significantly higher than that in the de-endothelialization group (p <0.01), while at two, four and eight weeks after transplantation, CD40 expression in the fresh and cryopreservation groups was significantly different from that in the de-endothelialization group (p <0.01).
  
  CONCLUSION:The calcium content in valve homografts was found to correlate with immune rejection. De-endothelialization could reduce immune rejection reactions and prevent calcification of aortic homograft valve.
authors.affiliation: Qingdao University, Qingdao.
authors.forename: Yanmeng
authors.initials: Y
authors.lastname: Lou
authors.affiliation: Qingdao University, Qingdao.|Cardiovascular Surgery Department, The Affiliated Hospital of Qingdao University, Qingdao.
authors.forename: Hui
authors.initials: H
authors.lastname: Jing
authors.affiliation: Qingdao Municipal Hospital, Qingdao, China.
authors.forename: Tianyi
authors.initials: T
authors.lastname: Wang
authors.affiliation: Qingdao University, Qingdao.|Cardiovascular Surgery Department, The Affiliated Hospital of Qingdao University, Qingdao.
authors.forename: Hongyan
authors.initials: H
authors.lastname: Wu
mesh_terms: D064591:Allografts; D000818:Animals; D001021:Aortic Valve / Q000187:drug effects* / Q000378:metabolism / Q000637:transplantation; D015415:Biomarkers / Q000032:analysis; D019013:CD40 Antigens / Q000276:immunology; D002118:Calcium / Q000032:analysis; D015925:Cryopreservation / Q000379:methods; D003451:Cryoprotective Agents / Q000494:pharmacology; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D004195:Disease Models, Animal; D005260:Female; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000295:instrumentation; D008297:Male; D011817:Rabbits; D011897:Random Allocation; D013997:Time Factors; D014022:Tissue Survival; D016042:Transplantation, Heterotopic / Q000379:methods
chemical_list: D015415:Biomarkers; D019013:CD40 Antigens; D003451:Cryoprotective Agents; D002118:Calcium; D004121:Dimethyl Sulfoxide