Adeghate E
Department of Human Anatomy, Faculty of Medicine and Health Sciences, United Arab Emirates University, Al Ain.
Anat Rec. 1998 Aug;251(4):448-59. doi: 10.1002/(SICI)1097-0185(199808)251:4<448::AID-AR4>3.0.CO;2-O.
One of the most determining factors for the survival of tissue grafts is an intact vasculature. This vasculature must, however, be linked to the circulation of the host animals for survival and growth to occur. The mechanism(s) of revascularization of pancreatic tissue grafts is still unclear and more so the process by which the host blood vessels anastomose with those of the graft. The microvasculature and revascularization of neonatal pancreatic tissue fragments transplanted into the anterior eye chamber of rats were investigated using conventional light and electron microscopy as well as the india ink perfusion method. Light microscopy demonstrated that the blood vessels of the host iris revascularized the transplants within 24 h of transplantation. Sinusoidal blood capillaries were observed to invade the peripheral parts of the grafts. The capillary encroachment from the iris into the graft continued through the second day of transplantation. The host-graft anastomosis developed completely and became prominent and conspicuous after the third day of transplantation. Many capillaries were observed to encroach into the graft from the iris. The vasculature of the graft was increased in comparison with that of normal pancreatic tissue. This increase was prominent especially around pancreatic islet and ductal cells which survived after transplantation. Blood cells observed in these vessels of the graft indicated a functional state. The ultrastructure of the intrinsic blood vessels of the graft was intact and showed the peculiar fenestrations normally seen in the blood vessels of endocrine tissues. These observations indicated that pancreatic tissue fragments transplanted into the anterior eye chamber of rats were revascularized within 24 h. The revascularization was completed at the end of the third day of transplantation when definitive blood vessels linked the circulation of the graft with that of the iris.
组织移植物存活的最关键因素之一是完整的脉管系统。然而，为了实现存活和生长，该脉管系统必须与宿主动物的循环系统相连。胰腺组织移植物的血管再生机制仍不清楚，宿主血管与移植物血管的吻合过程更是如此。利用传统光学显微镜、电子显微镜以及墨汁灌注法，对移植到大鼠眼前房的新生胰腺组织碎片的微血管和血管再生情况进行了研究。光学显微镜显示，宿主虹膜的血管在移植后24小时内就为移植物重新建立了血供。观察到窦状毛细血管侵入移植物的周边部分。从虹膜向移植物的毛细血管侵入在移植后的第二天仍在继续。宿主 - 移植物吻合在移植第三天后完全形成并变得显著。观察到许多毛细血管从虹膜侵入移植物。与正常胰腺组织相比，移植物的脉管系统有所增加。这种增加在移植后存活的胰岛和导管细胞周围尤为明显。在移植物这些血管中观察到的血细胞表明其处于功能状态。移植物固有血管的超微结构完整，呈现出内分泌组织血管中常见的特殊窗孔。这些观察结果表明，移植到大鼠眼前房的胰腺组织碎片在24小时内实现了血管再生。血管再生在移植第三天结束时完成，此时确定的血管将移植物的循环与虹膜的循环连接起来。
