The development of the fetal rat intestine and its reaction to maternal diabetes. I. Morphometrical analysis in normal conditions

In rodents, the fetal intestine develops rapidly during the last 5 days of gestation. The present investigation describes the events which occur in the duodenum, jejunum and ileum of fetal Wistar rat from day 16.5 to 21.5. The first villi and microvilli as well as endocrine cells already appear at 17.5 days in the duodenal mucosae. Goblet cells are detected at 18.5 days. The structure of the intestinal mucosa at 21.5 days is similar to that of adults. The evolution was quantified by morphometric analysis. The external and inner circumference, the length of the villi profile and the increased absorption area due to the villi profile were measured. We demonstrated that the total enlargement of the luminal surface area due to the villi and the microvilli in the duodenum of the fetus at 21.5 days is similar to that in the adult duodenum. This morphometric analysis could be used to detect possible disturbances in the development of the fetal intestine.