Abstract
The purpose of this study is to demonstrate possibilities to transplant the small intestine of newborn rat as a free graft without any vascular anastomoses. We evaluated optimal timing and site of the transplantation. In the first experiments, the small intestine was obtained from a newborn of Lewis stain rats. The newborn was divided into four groups according to their ages ; 0-day-old, 3-day-old, 5-day-old and 7-day-old. The donor jejunum, about 4cm in length, was implanted as a graft into the abdominal wall of syngeneic Lewis rats. More than 80% of the grafts were accepted and grew in the 0-day- and 3-day-old groups. In these groups, the majority of the grafts were histologically normal. However, the grafts from the 5-day- and 7-day-old groups disappeared at the recipient's abdominal wall in three weeks. In the second experiments, the grafts from the 3-day-old rats were transplanted into the three different sites syngeneically; the abdominal wall, the retroperitoneum and the omentum. Eighty-six percent of the grafts transplanted into the abdominal wall survived, while the survival rates of the grafts transplanted into the other sites were below 20%. From these results, we conclude that : 1) the small intestine of the newborn rats can be transplanted as a free graft into a syngeneic adult host, 2) the time limit of the newborn grafts for survival may be between 3 and 5 days of age in this rat model, and 3) the abdominal wall is one of the most suitable sites for transplantation of the intestine.
