消化管粘膜上皮の細胞回転に関する研究

正常マウスに於ける成績

抄録

Cell kinetics of the mucosal cells in various parts of the gastrointestinal tract was investigated in normal mice with 12-15 g of body weight using autoradiography with H3-thymidine and the following results were obtained:
1) Mitosis was observed only in the following area: stomach (5×14μ to 12×14μ), duodenum (1 to 5×14μ), jejunum (1 to 7×14μ) and ileum (1 to 4×14μ)-all figures represent the distance from the muscularis mucosa. In mucosal cells of the mice sacrificed 1 hour after intraperitoneal injection with H³-thymidine, H³-labeled cells were found only the same area as above described. These results indicate that the cells in this area consist of the proliferative compartment.
2) From the analysis of the fraction of mitoses labeled in the mucosal cells of the mice sacrificed at various time following single injection with H³-thymidine, the following results were obtained:
3) In gastric mucosa, distribution of the labeled cells spread out both to the gastoric pit and to the muscularis mucosa and attained the level of the muscularis mucosa at 21 hours following single injection with H³-thymidine. In apex of the gastric pit, labeled cells are found in the autoradiogram obtained from the mice sacrificed 46 hours after the injection. In the intestinal mucosa, distribution of the labeled cells spread out only to the intestinal villi, and attained at the apex at 43 hour in duodenum, 43 hour in jejunum and 46 hour in ileum after the injection. Autoradiograms obtained from the mice sacrificed 73 hours after the injection, percentage of the labeled cells was low at any part of the mucosa, suggesting that most of the labeled cells were removed by this time.
4) Mean grain count of the labeled cells in the proliferative compartment was reduced exponentially during the time course from single intraperitoneal injection with H³-thymidine at either part of the intestinal or gastric mucosa.
Mean generation time of the mucosal cells of proliferative compartment of the stomach, duodenum, jejunum and ileum calculated from these results were 35, 14, 14 and 14 hours, respectively.
The analysis of the mean grain counts both in the proliferative and in the functional compartment revealed that the cells of the latter compartment mitosed at least once in the former compartment on an average.