| Objectives(1)To observe the histomorphologic development of human fetus small intestine (duodenum-, jejunum and ileum). (2) To study the developmental regularities and heterogeneity of mast cells in fetus small intestine. (3) To study the distribution and developmental regularities of Substance P (SP) and Calcitonin Gene-Related Peptide (CGRP) - IR peptidergic nerves in fetus small intestine. ?To approach the relationship of the mast cells(MC) and SP- IR and CGRP- IR peptidergic nerves in fetus small intestine Methods (1)Hematoxylin-Eosin (HE) staining. (2)Toluidine blue (TB) staining. (3) Immunohistochemical ABC method. Results. (1) The histological differentiations in small intestine were proceed from the beginning to the end .At 12nd week, the fairly developed lobe-shape intestinal villus were formed hi duodenum, Digital-shape villus had also seen in jejunum, but lower-conus body configur appeared in ileum. At 15th week, intestinal gland in duodenum extend into submucosa to form mucous cell's duodenal gland. At 21st week, mucosa muscularis appearedgradually ,there were four layers in the wall of small intestine. (2)The granular of the immaure MC were pale violet and the granular of the mature MC were strong violet in color by TB staining. At 16 th week, connective tissue MC (CTMC) appeared occasionally in connective tissue of submucosa and muscular layer in small intestine. But the time of MC in mucosa (MMC) appeared at 18th week, So MC has heterogeneity. At 22nd week, the two types of MC were both active. They were distributed in the surrounding blood vessels and ganglions, etc. The verge of some MC were unclear, they were degranular phenomena. MC may play an important part in regulating blood circulation and sensation. (3)At 14th week, The SP-IR and CGRP-IR nerve fibers and cells appeared occasionally in the myenteric and submucous plexuses in small intestine, and the responds were gradually strong. Neuron showed from light to deep brown, and nerve fibers were presented as varicose and liner profiles. On the corresponding site of serial sections of SP-IR , CGRP-IR immunohistochemistry, some of them were coexisted in one nerve fiber and cells. (4)On the corresponding site of serial sections of TB special staining and SP- DR^ CGRP- IR immunohistochemistry, some of MC showed SP-IR, CGRP-IR immunoreactivity. Conclusion (1)The histologic form of small intestine appeared obviousely changing in developing fetus, Its differentiation proceeds successively from duodenum to jejunum and ileum. (2)There were two kinds of MC--mucosa MC and connective tissue MC, which showed heterogeneity.(3)The SP-IR and CGRP-IR peptidergic nerves were seen in fetus small intestine. The SP-IR and CGRP-IR nerve fibers and cells appeared in the myenteric and submucous plexuses, but their development and distributions were different. (4) Some of MC in fetus small intestine showed SP^ CGRP- immunoreactivity. MC may play an important part in regulating blood circulation and sensation. |
