Proliferation and distribution of myoepithelial cells during atrophy of the rat sublingual gland.
BACKGROUND
The present study was aimed to determine the proliferation and distribution of myoepithelial cells during atrophy of rat sublingual glands.


METHODS
The excretory duct of the right sublingual gland of rats was doubly ligated with metal clips to induce atrophy in the gland. The atrophic sublingual glands were taken from 1 to 28 days after duct ligation and examined with single immunohistochemistry for actin as a marker of myoepithelial cells and with immunohistochemical double staining for actin and proliferating cell nuclear antigen (PCNA) as a marker of proliferating cells.


RESULTS
In unligated sublingual glands, myoepithelial cells embraced acini and intercalated ducts, but not striated and interlobular excretory ducts. In the early stages of atrophy, myoepithelial cells surrounded small ducts but not large ones. However, in the later stages of atrophy, myoepithelial cells were also observed at the periphery of the large ducts. The immunohistochemical double staining showed that there were PCNA-positive myoepithelial cells in the normal as well as in the atrophic sublingual glands. However, the PCNA labeling indices of myoepithelial cells were low in the unligated and atrophic sublingual glands, and there were no statistically significant differences in these labeling indices.


CONCLUSIONS
The observations suggest that the distribution of myoepithelial cells change during atrophy of rat sublingual glands and that myoepithelial cells have low proliferative activity in both the normal and atrophic condition of rat sublingual glands.
Takahashi
S
S
Department of Oral Health Science, Hokkaido University Graduate School of Dental Medicine, Sapporo, Japan.tshigeru@den.hokudai.ac.jp
Shinzato
K
K
Domon
T
T
Yamamoto
T
T
Wakita
M
M
D000199:Actins / Q000032:analysis; D000704:Analysis of Variance; D000818:Animals; D001284:Atrophy; D002455:Cell Division; D004847:Epithelial Cells / Q000166:cytology / Q000473:pathology* / Q000502:physiology; D007124:Immunoenzyme Techniques; D008026:Ligation; D008297:Male; D009130:Muscle, Smooth / Q000166:cytology; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D013361:Sublingual Gland / Q000737:chemistry / Q000166:cytology* / Q000473:pathology*
D000199:Actins; D018809:Proliferating Cell Nuclear Antigen