Thompson S C, Mandel T E
Walter and Eliza Hall Institute of Medical Research, Royal Melbourne Hospital, Parkville, Victoria, Australia.
Transplantation. 1990 Mar;49(3):571-81. doi: 10.1097/00007890-199003000-00019.
The possibility of using xenogeneic islets for transplantation in insulin-dependent diabetes mellitus (IDDM) necessitates characterization of their potential for growth and functional differentiation. Fetal pig pancreas (FPP) of various gestational ages was examined with respect to morphology, ability to produce insulin before and during culture, and development and function in nude mice. Insulin-containing beta cells were present, but distinct islets were not apparent in FPP even in late gestation, and did not develop during culture. FPP remained viable and produced insulin for up to 30 days in vitro. Mitotic figures were seen in cultured tissue. Culture on a gelfoam raft resulted in more viable tissue than free-floating culture. Culture in a high concentration of O2 (90% O2/10% CO2) was detrimental compared with culture in 10% CO2 in air. Responses to static incubation in secretagogues showed that IMBX, theophylline, and tolbutamide all stimulated insulin secretion, but high glucose concentration (5 g/L), arginine, and leucine did not. The potential of this tissue for growth and its ability to regulate blood glucose levels appropriately were tested in athymic (nu/nu) mice. Pancreatic tissue from fetuses as young as 4 weeks gestation showed growth after transplantation into athymic mice, with representation of the major pancreatic endocrine cells demonstrated by selective immunochemical staining. The increase in the size of the grafts showed an impressive proliferative capacity, and histology confirmed mitotic activity and islet structure in the graft. The amount of endocrine tissue in grafts reflected the condition of the explants at the time of grafting, and prolonged culture times were detrimental to eventual graft size. Functional capability of the grafted FPP to release insulin in response to hyperglycemia was tested by transplantation into mice made diabetic with streptozotocin. Blood glucose levels, animal weights and survival, and the histological appearance of the tissue after graft nephrectomy indicated that either fresh tissue or tissue cultured for up to 8 days (Gelfoam; 10% CO2 in air) had better eventual graft function then FPP grown in 90% O2 or transplanted as a secondary graft following an interim period to allow gestational maturation in a nondiabetic nu/nu host. Return to euglycemia took 3-4 months after transplantation of FPP. The in vitro characteristics of FPP are similar to those reported for human fetal tissue, and since FPP is capable of growth and proliferation in vivo and has the ability to normalize hyperglycemia, further investigation of FPP to establish its suitability as a source of xenogeneic insulin-secreting tissue for human transplantation is warranted.
在胰岛素依赖型糖尿病（IDDM）中使用异种胰岛进行移植的可能性，需要对其生长和功能分化潜力进行表征。对不同胎龄的胎猪胰腺（FPP）进行了形态学、培养前后产生胰岛素的能力以及在裸鼠中的发育和功能研究。FPP中存在含胰岛素的β细胞，但即使在妊娠晚期也未见到明显的胰岛，且在培养过程中也未发育形成。FPP在体外可存活长达30天并产生胰岛素。在培养的组织中可见有丝分裂象。在明胶海绵筏上培养比悬浮培养能产生更多存活的组织。与在空气中10%二氧化碳培养相比，在高浓度氧气（90%氧气/10%二氧化碳）中培养有害。对促分泌剂静态孵育的反应表明，异丁基甲基黄嘌呤（IMBX）、茶碱和甲苯磺丁脲均能刺激胰岛素分泌，但高葡萄糖浓度（5g/L）、精氨酸和亮氨酸则不能。在无胸腺（nu/nu）小鼠中测试了该组织的生长潜力及其适当调节血糖水平的能力。妊娠4周的胎儿胰腺组织移植到无胸腺小鼠后显示出生长，通过选择性免疫化学染色证实了主要胰腺内分泌细胞的存在。移植组织大小的增加显示出令人印象深刻的增殖能力，组织学证实移植组织中有有丝分裂活性和胰岛结构。移植组织中内分泌组织的量反映了移植时外植体的状况，延长培养时间对最终移植组织大小不利。通过将移植到用链脲佐菌素诱导糖尿病的小鼠体内，测试移植的FPP对高血糖反应释放胰岛素的功能能力。血糖水平、动物体重和存活率以及移植肾切除术后组织的组织学外观表明，新鲜组织或培养长达8天的组织（明胶海绵；空气中10%二氧化碳）最终移植功能比在90%氧气中培养或在非糖尿病nu/nu宿主中经过一段妊娠成熟中期后作为二次移植的FPP更好。移植FPP后3 - 4个月血糖恢复正常。FPP的体外特性与报道的人胎儿组织相似，并且由于FPP在体内能够生长和增殖且具有使高血糖正常化的能力，因此有必要进一步研究FPP以确定其作为人移植用异种胰岛素分泌组织来源的适用性。
