3-DIMENSIONAL STRUCTURE AND CELL-KINETICS AT DIFFERENT SITES OF RAT INTESTINAL REMNANTS DURING THE EARLY ADAPTIVE RESPONSE TO RESECTION

The early phase of the morphological adaptation of rat ileum after a 60% proximal resection was studied using microdissection and cell labeling techniques. Resected rats and sham-operated controls were killed 2, 4, 6, 10 and 12 days after surgery. I.p. injections of 3H-thymidine were carried out 24 or 12 h prior to sacrifice. In the latter groups mitotic arrest was achieved by vincristine. A stereomicroscope was used to measure and calculate the following parameters: intestinal diameter; villus: height, width, breadth at base and apex, surface, enterocytes/100 .mu.m length, cell pool, number of villi and absorptive surface/mm2 serosal area; crypt: length, enteroblasts per 100 .mu.m length and per column, cell columns and mitoses per crypt, cell pool, crypts and mitoses per unit serosal area and cell kinetics: migration rate, villus transit time. To test the influence of treatments, postoperative time course and the location of the intestinal segment and their possible interactions, factorial analyzes of variance were carried out on the parameters investigated.