EFFECT OF HEPATOCELLULAR TRANSPLANTATION VIA UMBICAL VEIN IN FETAL RATS OF CONGENITAL METABOLIC DISEASE

遗传性肝酶缺乏症在亲代时期发生和发展，需要产前治疗。我们研究了经脐静脉输注肝细胞进行产前肝细胞移植的效果。本实验选用了一种因肝微粒体中缺乏L-古龙内酯氧化酶而不能在肝脏中合成抗坏血酸的突变体。同时，我们还研究了胎肝细胞同种移植到成年SHR脾中的细胞色素P450的表达。1.取与之同源但可合成AsA的ods-^+/+大鼠肝细胞，于孕18d剖腹，取其中一只胚胎上方的子宫壁固定于腹壁。在子宫壁和羊膜上加小切口后，拔除脐带，在显微镜下用30号针将2~4×10~5个肝细胞注入脐静脉。给大鼠喂以含有…的标准饲料术后持续6周以上。在6只存活6周的受体中，有2只大鼠发病较晚，停药后存活时间是对照组的两倍。这种效应被认为来自于移植到受体肝脏中的肝细胞。II：取孕20天自发性高血压大鼠(SHR)胎肝细胞，移植于受体成年SHR脾内。6周后，受者脾的形态检查显示，红髓内可见大量肝细胞，呈明显的索状结构。肝细胞移植脾在移植后2~10周可表达多个家族的细胞色素P450蛋白。因此，移植的肝细胞组织似乎生长和发展了细胞色素P450代谢系统。如果在产前诱导免疫耐受，这种治疗方法对反复同种异体肝细胞移植可能是非常有利的。较少

Prenatal treatment is needed for inherited liver enzyme deficiency which occurs and progresses at parental period. We studied effects of prenatal hepatocellular transplantation by infusion of hepatocytes via the umbilical vein, using ODS-^<od>/od rat, which is a mutant unable to synthesize ascorbic acid (AsA) in the liver because of a lack of L-gulonolactone oxidase in the liver microsomes. And also we studied the expression of cytochromes P450 of fetal hepatocyte transplanted into adult SHR spleen syngenitically. I : Hepatocytes were isolated from ODS-^+/+ rat, which is congeneic to ODS-^<od>/od but can synthesize AsA.Laparotomy was performed on female ODS-^<od>/od rats at 18 days of gestation, and uterus wall above one of the fetuses was fixed to abdominal wall. After small incision was added to the uterus wall and anmion, umbilical cord was drawn out and 2-4x10^5 hepatocytes were infused to the umbilical vein by 30 gauge needle under microscopy. Rats were fed a standard diet contain … More ing AsA for 6 weeks after operation. Out of 6 recipients which were born alive and survived for 6 weeks, 2 rats showed late onset of disease and survived twice as long as controls after the cessation of AsA administration. This effect is thought to be derived from hepatocytes implanted in the liver of recipient. II : Fetal hepatocytes were harvested at 20 days of gestation from spontaneously hypertensive rats (SHR) and then transplanted into recipient adult SHR spleens. Morphological examination of the recipient spleens revealed that after 6 weeks, large masses of hepatocytes were present in the red pulp with apparent cord-like structures. Of major significance was the fact that hepatocyte transplanted spleens were able to express several families of cytochrome P450 proteins 2-10 weeks after transplantation. Thus, the transplanted hepatocyte tissue appeared to grow and develop a cytochrome P450 metabolic system. This therapy might be of great advantage for repeated allogeneic hepatocyte transplantation, if immunological tolerance is induced at prenatal period. Less