Regeneration of tubular complex is promoted by a free space.
OBJECTIVE
Regeneration of the pancreas is initiated by the tubular complexes that consist of a cluster of epithelia surrounded by the mesenchymal cells. They have the potential to become pancreatic lobes, but their growth stops before the complete regeneration of the organ. To elucidate the possibility that we could promote the regeneration of the pancreas, the potential for growth or differentiation of tubular complex was analyzed.


METHODS
The intact lobes were growing around the silk knot after ligation of the pancreas in adult mice. To develop this reaction to a quantitative assay, tubular complexes were induced on the silk strings in the pancreas and were growing into a free space under the silicon cover. The proliferation and differentiation of new lobes with or without the space were analyzed.


RESULTS
The number of tubular complexes, which express PDX-1, was increased 5.4 times by the space effect. The proliferating cell nuclear antigen labeling index of acinar cells was 1.7 times stimulated, but that of tubular complex was not changed. The amputated pancreas recovered 49.5% of the resected part under the silicon cover; however, it remained the same weight without the cover.


CONCLUSIONS
The proliferation and differentiation of tubular complex are promoted by a free space.
Kitamura
Tetsuhiro
T
Department of Molecular Medicine, Osaka University Medical School, Osaka, Japan.
Asanuma
Nobuyuki
N
Inaba
Makiko
M
Otsuki
Michio
M
Kasayama
Soji
S
Kouhara
Haruhiko
H
Kawase
Ichiro
I
D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D004847:Epithelial Cells / Q000502:physiology; D008026:Ligation; D008297:Male; D008648:Mesoderm / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D009929:Organ Size; D010179:Pancreas / Q000166:cytology* / Q000502:physiology* / Q000601:surgery; D019736:Prostheses and Implants; D012038:Regeneration / Q000502:physiology*; D012825:Silicon; D047011:Silk
D047011:Silk; D012825:Silicon