Establishment Of A New Miniature Porcine Model For Controlled Cardiac Deceased Donor And In Vitro Preservation Research In Kidney

Worldwide,shortage of donor organ has been becoming the main contradiction of the development of organ transplantation, which is more prominent in China. With the reforming and perfecting of system, upgrading of people’s quality of law, the deceased donor organs gradually withdraw from the historical stage in China, and donation after cardiac death(DCD) increases year by year, becoming the main source of donor organs in China.DCD donor organs are heavily suffered from ischemia-reperfusion injury, increasing the risk of delayed graft function or primary graft failure after transplantation. How to reduce this type of donor organs injury, and the assessment of organ activity before transplant are hotspots of current research. Large animal experimental research simulate the physiological and pathological process of human organs better, is the best model for study of DCD donors. But variations exist in the way of death induction, physiological parameter monitoring, and acquisition of donor organs in view of the DCD donors. Cardiac death donor model is sensitive in the way of death induction and time, so we established a more stable and controllable type miniature pig cardiac death donor model on the basis of previous studies.Previous research has confirmed that mechanical perfusion preservation can effectively reduce the donor organs of ischemia-reperfusion injury comparing to traditional cryogenic static save(cold storage, CS). But for the DCD donors, whether low-temperature perfusion or room temperature perfusion low is more applicable still needs further research. PURPOSESEstablishment of porcine model for controlled Cardiac Deceased Donor by using in vitro organ perfusion equipment designed by laboratory.1. Establishment of no heart donor animal model. Coronary artery ligation method is adopted to establish the miniature pig preparation type controlled heart donor animal models. Monitoring hemodynamic, blood gas analysis, and the time of death before the circulatory failure. The donor liver/kidney pathological tissue biopsy and pathological damage analysis are done in the different time after cardiac arrest for donor organs(liver/kidney).2.DCD for renal perfusion in vitro machinery preservation at room temperature(37 ℃) and low temperature(4 ℃), respectively, comparing two perfusion methods in reducing the effect of DCD for renal injury. METHODS1. The three groups of wuzhishan miniature pig(2 ~ 4 months), each three for a group. Assisted respiration after general anesthesia, the left descending artery in the heart open chest line separation technique, separation for liver and kidneys, and abdominal aorta intubation, connecting the HC- A liquid preparation II infusion, prepared in the depth of anesthesia after stop breathing machine, liquid and drug support, and left descending artery ligation heart at the same time, to breathing heartbeat stop completely, record during the heart rate, systolic pressure, diastolic blood pressure, central venous blood pressure, blood oxygen saturation and regularly take on blood gas analysis. After cardiac arrest respectively 0 min, 15 min, 30 min, start HC- A fluid infusion, II to hepatorenal grey color, after taking art combined kidney-liver; After the completion of the infusion of donor liver and kidney biopsy.2. For the kidney, kidneys are randomly divided into two groups, one group II with HC under 4 ℃- A fluid mechanical perfusion in vitro preservation, another group under 37 ℃ with KH perfusion fluid(Krebs- Henseleit k-h liquid) and in vitro mechanical infusions kept. Monitoring of kidney urine in different time of the infusion fluids, detection of perfusion fluid LDH, kidney puncture, detecting the content of SOD and GSH in the organization, and the end time of puncture after 6 h donor kidney tissue pathology analysis. RESULTS1. The heart rate, systolic pressure, diastolic blood pressure, central venous pressure, blood oxygen saturation, co2 partial pressure changed significantly, respiratory failure and death occurs 7 minutes after left descending coronary artery ligation and cease of assisted respiration.2. K-H fluid normal temperature mechanical perfusion in vitro compared with HC- A II in vitro perfusion liquid low temperature preservation, can clearly improve the cells of ischemia and hypoxia of donor organs, reduce tissue injury, improve microcirculation status. CONCLUSIONS1. A new model of donor respiratory cycle failure stability, can be controlled, no drug side effects, died after cardiac arrest in about 7 minutes. The model is applicable for the further study of the donor organs.2.The room temperature mechanical perfusion in vitro can improve DCD cells in ischemia and anoxia of donor organs, reducing tissue injury compared with in vitro perfusion method at low temperature.