Basic Studies on Liver Transplantation and Liver Preservation

研究一：免疫抑制剂FK506对猪肝脏热缺血损伤的保护作用作为肝脏保存的研究。研究二：幼猪原位肝移植后溃疡发生率很高。因此，我们研究了猪肝移植后胃溃疡的发病机制及迷走神经切断幽门成形术对其的预防作用。研究三：为有效预防排斥反应，同种异体肝移植受者通常接受终生免疫抑制治疗，偶尔还会出现危及生命的并发症。长期免疫抑制治疗的这些并发症是可以避免的，如果有可能达到抗原特异性的无应答状态，从而促进这种耐受性。我们曾试图通过在手术结束时将供者的脾细胞注射到受者的脾中，并在术后仅给予环孢素7天来诱导这种耐受性。Mate…第一项研究：选用体重在18-22公斤的公猪或母猪。在诱导肝脏缺血性损伤前，行侧侧门腔分流术，经胆总管插管。门静脉和肝动脉在肝门处交叉夹闭，造成3h热缺血。实验动物分为两组：I组(n=7)为对照组，II组(n=5)注射FK506(1 mg/kg，i.m)。缺血前4天。观察动物存活率、血清谷草转氨酶(S-GOT)、血清乳酸脱氢酶(S-LDH)、肝细胞转运蛋白(BSP)转运活性、胆汁流量、中性粒细胞依赖化学发光及肝脏组织学变化。研究二：11只体重14~21 kg的雌性仔猪进行原位肝移植。动物分为对照组(4头)和迷走神经切断组(7头)。迷走神经切断组采用双侧迷走神经干切断术和叶成形术。两组术后均给予环孢素10 mg/kg口服。第三项研究：为研究免疫耐受的诱导，对体重19~20 kg的雌性仔猪实施了5例迷走神经切断+幽门成形术的原位肝移植。将动物随机分为对照组(3头)和实验组(术后经脾动脉注入供体脾细胞2×109)和术后7天环孢素组(对照组)。相比之下，II组的5头猪全部存活7天以上。II组BSP的肝转运活性和胆汁流量均有改善。I组血液的化学发光在再灌流后明显增强。相比之下，II组的血液化学发光没有明显增加。I组肝细胞空泡变性，肝窦扩张，而II组肝组织学改变轻微。研究二：未行迷走神经切断幽门成形术的对照组，溃疡发生率为100%。溃疡大量累及贲门小弯，所有四只动物都死于大量胃肠道出血。迷走神经切断组未见胃溃疡。术后一年仍有一头猪存活。其余分别死于肠梗阻(2头，存活5天和28天)、肝坏死(1头，存活3天)、化脓性胆管炎(2头，存活34天和84天)、动脉插管脱出意外出血(1头，3天)。迷走神经切断幽门成形术预防幼猪原位肝移植胃溃疡效果显著。研究三：诱导免疫耐受的实验结果尚不清楚。接受供者脾细胞移植的实验组存活时间分别为第28天和84天。相比之下，对照组的存活时间分别为第3、5和34天。较少

First Research : The protective effect of the immunosuppressive drug FK506 on warm ischemic injury of pig liver was studied as research of liver preservation.Second Research : The incidence of ulcer is very high after orthotopic liver transplantation in young pigs. Therefore we studied the pathogenesis of gastric ulcer following pig liver transplantation and its prevention by vagotomy-pyloroplasty.Third Research : To prevent rejection effectively, allograft recipients usually receive life-long immunosuppressive treatment, which may occasionally be associated with life-threatening complications. These complications of long-term immunosuppressive treatment would be avoided if it were possible to achieve a state of antigen-specific unresponsiveness that would promote a condition such tolerance we have attempted to induce such tolerance by injection of donor's spleen cells to recipients spleen at the end of operation and by administration of cyclosporin for only 7 days postoperatively.Mate … More rials and MethodsFirst Research : Male or female pigs weighing from 18 to 22 kg were used. Before induction of ischemic injury to the liver, side-to-side portocaval shunt and cannulation through the common bile duct were performed. Warm ischemia for 3 hours was induced by cross-clamping the portal vein and the hepatic artery at the hepatic hilus. The animals were divided into two groups : Group I pigs (n=7) served as the control, Group II (n=5) was given FK506 (1mg/kg, i. m.) for 4 days prior to being subjected to the ischemia. Survival rate, serum glutamic oxaloacetic transaminase (S-GOT), serum lactic dehydrogenase (S-LDH), hepatic transport activity of BSP, bile flow, neutrophil dependent chemiluminescence, and histologic examination of the liver were serially studied.Second Research : Eleven orthotopic liver transplantations were performed on female young pigs weighing from 14 to 21 kg. The animals were divided into control (4 pigs) and vagotomy (7 pigs) groups. Bilateral truncal vagotomy and phyloroplasty were performed in pigs of vagotomy group. Cyclosporin (10 mg/kg, orally) was given postoperatively in the both groups. A necropsy was performed when recipient pigs died.Third Research : To study the induction of immuno-tolerance, 5 orthotopic liver transplantations with truncal vagotomy and pyloroplasty were performed on female young pigs weighing from 19 to 20 kg. The animals were randomized into control (3 pigs) which received a 7-day postoperative course of cyclosporin (10 mg/kg, orally) and the experimental group which received the injection of donor's spleen cells (2^*10^9) to the recipient spleen via the splenic artery at the end of operation and a 7-day postoperative course of cyclosporin.ResultsFirst Research : Six of 7 animals in Group I (control) died within 7 days. In contrast, all of the 5 pigs in Group II survived more than 7 days. Hepatic transport activity of BSP and bile flow were improved in Group II. The chemiluminescence of blood samples from Group I increased markedly after reperfusion. In contrast, marked increase of the chemiluminescence of blood from Group II was not observed. Vacuolar degeneration of the hepatic cells and dilatation of the sinusoid in Group I were revealed histologically, similar histological changes of the liver in Group II, however, were slight.Second Research : In the control pigs which did not have vagotomy-pyloroplasty, the incidence of the ulcer was 100%. The ulcers involved the cardia-lesser curvature massively and all four animals died of massive gastrointestinal bleeding. In the vagotomy group, gastric ulcer was not observed. One pig is still alive one year after operation. The others died of ileus (two pigs, survived in days 5 and 28), liver necrosis (one pig, 3 days), suppurative cholangitis (2 pigs, in day 34 and 84), accidental bleeding due to falling out from arterial cannulation (one pig, 3 days). Vagotomy-pyloroplasty prevented gastric ulcer very effectively in young pig orthotopic liver transplantation.Third Research : Results of the experiment to induced the immunoto-lerance are not clear yet. Survival of the experimental group which received donor's spleen cells was in days 28 and 84. In contrast, survival of the control group was in days 3, 5 and 34. Less