1995 Volume 32 Issue 4 Pages 241-251
To demonstrate morphologically the functional difference in each intestinal part, 27 (starter stage)-and 113 (developer stage)-day-old male Single Comb White Leghorn chickens were fasted for 3 or 7 days. After the end of each fasting period, the villous height and the fine structure of absorptive epithelial calls in the duodenum, jejunum and ileum were compared using light and electron microscopies. On the post-hatching developmental changes of the villous height in the normal control, the duodenum had the highest villi at starter stage followed by undeveloped lower jejunal villi, while the latter showed a marked growth rate up to the developer stage. This explains that the vigorous absorptive part would be mainly the duodenum in early life stage and then extend to the jejunum with increasing age. However, after fasting treatment these proximal intestines had thought to have a high absorptive ability revealed a dramatic reduction of the villous height. This suggests that among the intestinal parts, the higher the intestinal absorptive ability during the normal feeding is, the more rapidly the intestinal villous height is reduced by fasting. In fine structural alterations, the epithelial cells in the duodenum had large lysosomal supranuclear vacuoles even after 3 days fasting. On the other hand, by the first 3 days fasting the jejunal cells showed the lamellar bodies thought as a precursor of vacuoles and had typical vacuoles after next 4 days fasting. These suggest that among the intestinal epithelial cells, the higher the cellular absorptive ability during the normal feeding is, the more rapidly the lysosomal vacuoles grow larger in size by fasting.
Compared with the alterations of villous height and ultrastructure of epithelial cells observed in the proximal intestines, the ileum showed an almost constant vilious height and no typical vacuoles but well-developed Golgi apparatuses in cells after fasting. These findings lead to the possibility that the ileum appears to be inactive in absorptive function and it might have another specific function in addition to the conventional absorptive function.