SEQUENTIAL ISOLOGOUS ORGAN-TRANSPLANTATION IN INBRED RATS - PANCREATICODUODENAL TRANSPLANTS

A total of 847 inbred Lewis rats of mixed sex were used in this pancre aticoduodenal (Pd) donor aging study. Pd grafts were taken from 9- to 12-month-old donors and transplanted into 3-month-old recipients (thus , the first generation Pd graft, or 1 Pd). After 9 to 12 months, the s ame Pd grafts were again harvested and transplanted into 3-month-old r ats (thus the 2 Pd generation). This cycle was repeated to obtain the 3, 4, and 5 Pd series, Sequential transplantation was able to extend t he Pd grafts' mean survival time to 32 months for fourteen 4 Pd grafts , and to 39.2 months for four 5 Pd grafts (the longest lived graft sur vived for 42 months). The pancreas and duodenal sections of the grafts remained normal throughout the entire study. However, the aortic sect ions of the grafts (which were harvested to include the superior mesen teric and celiac arteries) all exhibited moderate to massive atheroscl erotic changes by the 5 Pd mean survival age of 39.2 months. Such hist ological changes commenced even before 21 months of Pd graft age in so me animals, gradually progressing to dilation of the aorta (and subseq uent narrowing of aortic tributaries), as well as formation of an eggs hell like inner membrane shielding the aortic intima, by 42 months, Su ch atherosclerotic changes precluded transplantations beyond the 5 Pd series.