同种异体大鼠骨髓及肝联合移植动物模型的建立及意义

Establishment and evaluation of allogenic animal bone marrow and orthotopic liver transplantation model in rats

目的通过建立同种异体大鼠骨髓及肝联合移植动物模型，探讨提高大鼠肝移植模型的稳定性和存活率的方法及可行性。方法将SD大鼠（♂）、Wistar大鼠（♀）分成三组：Ⅰ组大鼠Kamada“二袖套法”行SD→Wistar大鼠肝移植；Ⅱ组Wistar大鼠（♀）TBI（11Gy），4h后输入SD大鼠（♂）BMC（8×10^7），28d后Kamada“二袖套法”行SD→Wistar大鼠肝移植；Ⅲ组Wistar大鼠（早）TBI（7Gy），4h后输入SD大鼠（♂）BMC（8×10^7），2d后CTX（50mg／kg体重）腹腔注射，28d后Kamada“二袖套法”行SD→Wistar大鼠肝移植。分别于BMT后10、20d通过PCR方法检测Ⅱ组和Ⅲ组Wistar大鼠体内的SD大鼠源性Y染色体特异性片段。并比较3组大鼠肝移植术后1周生存率、生存状况及生存时间。结果Ⅱ组和Ⅲ组大鼠外周血均检测出SD大鼠源性嵌合体。DTH检查显示对SD大鼠产生免疫耐受。肝移植结果显示，Ⅰ组大鼠均在4～5d死亡，而Ⅱ组和Ⅲ组大鼠1周存活率为80．0％和84、2％，但Ⅱ组的生存状况不如Ⅲ组。结论应用7GyTBI＋CTX＋供体BMT可成功建立同种异体大鼠嵌合体模型，诱导特异性免疫耐受，大大提高肝移植术后大鼠的生存状况及生存时间。

Objective To establish the allogeneic animal bone marrow and orthotopic liver transplantation model in rats, and investigate the method and feasibility for enhancing the stability and prolon- ging the survival time of liver transplantation model in rats. Methods SD rats （donor, ♂ ） and Wistar rats （ recipient, ♀ ） were randomly and averagely divided into three groups and conditioned by three methods： In group Ⅰ , orthotopic liver transplantations in rats were performed using modified Kamada＇s two-cuff technique; In group Ⅱ, Wistar rats （recipient, ♀ ） were induced with sublethal total body irradiation （TBI,11 Gy）,and in group Ⅲ,Wistar rats were induced with TBI （7 Gy）,followed by infusion of SD （donor, ♂ ） rat hone marrow cells （8 × 10^7） within 4 h, then administered with cytoxan （CTX, 50 mg/ kg） intraperitoneally 2 days later. According to the Gene Bank,the specific primer of rat SRY gene was designed. Recipient rats were detected for donor origin cells in the peripheral blood lymphocytes on day 10 and 20 by polymerase chain reaction （PCR）. The PCR product was analyzed by electrophoresis. Orthotopic liver transplantations were performed in rats 28 days later. The tolerance mechanism through delayed type hypersensitivity （DTH） and survival time after liver transplantation in the rats was explored. Results Chimera of SD rats could be found in the peripheral blood lymphocytes of the tolerance Wistar rats in groups Ⅱ and Ⅲ. Wistar rats were specifically tolerant to the SD rats in DTH. The rats in group Ⅰ died after 4-5 days ,and the one-week survival rate in groups Ⅱ and Ⅲ was 80% and 84.2% respectively. Conclusion Treatment of 7 Gy TBI and the injection of CTX （50 mg/kg） plus donor bone marrow transplantation （BMT） can successfully establish rat chimera model, induce specific immune tolerance and greatly prolong the survival time of liver transplantation model in rats.