Ultrastructural findings in the wound healing of the colonic mucosa of rabbits.
The wound healing of the rabbit colonic mucosa after experimental excision was observed with the electron microscope. Between 5 and 7 days, considerable numbers of undifferentiated mesenchymal cells (group I), differentiating muscle cells (group II) and histiocyte-like cells (group III) appear in the regions where the muscularis mucosae is re-establishing. Our electron micrographs indicate that group I cells are stem cells which differentiate to group II cells involved in muscle regeneration or to group III cells involved in phagocytosis. The mitotic proliferation of pre-existing smooth-muscle cells at the ulcer margin does not seem to be the major reason for the re-establishment of the muscular layer. Multinucleated cells occurring in this healing mucosa are considered to be formed by successive fusions between the group III cells and to play a role in enclosure of cell debris such as fragments of elastin.
Mori
N
N
Department of Anatomy, University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Japan.
Yoshizuka
M
M
Ueda
H
H
Ono
E
E
Umezu
Y
Y
Fujimoto
S
S
D000818:Animals; D003106:Colon / Q000166:cytology / Q000502:physiology* / Q000648:ultrastructure; D007413:Intestinal Mucosa / Q000166:cytology / Q000502:physiology* / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D011817:Rabbits; D014945:Wound Healing