Changes in the activity of stem/progenitor cells in the rat submandibular gland following ligation of the main excretory duct / 中国组织工程研究

ABSTRACT

BACKGROUND:Fewer ethical issues exist in adult stem cells, and some operating technologies are relatively mature. Therefore, to construct tissue-engineered salivary glands using adult stem cells is very attractive and seductive with an extremely important application prospect. OBJECTIVE:To establish a rat model of salivary gland injury by ligation of the main excretory duct of the submandibular gland and to explore the existing feasibility and location of adult stem cells in the injured models. METHODS:The main excretory duct of the right submandibular glands was ligated in Sprague-Dawley rats. After 1 week, rats were kil ed to remove the bilateral glands that were then subject to hematoxylin-eosin staining, PAS glycogen staining and immunohistochemical staining for determination of CK-19, Bcl-2, Ki-67. After that, we compared the normal submandibular gland with the damaged model after ligation of main excretory duct. RESULTS AND CONCLUSION:The rats showed differences in the volume and mass of the affected and normal submandibular glands. The normal submandibular gland was oval, ruddy, smooth, soft with an intact envelop. After ligation, the injured submandibular gland appeared to have atrophy with dark red in color, irregular morphology, envelop congestion, and rough texture;the surrounding vessels showed compensatory expansion. PAS-positive gland cells disappeared, CK-19-postive smal duct epithelial cells proliferated, and laminin-positive cells that were rarely found in the normal gland existed around the duct. In addition, Bcl-2/Ki-67 positive cells were both increased. These findings indicate that stem/progenitor cells may be located in the periductal area of the submandibular gland;and the model of submandibular gland injury established by ligation of the main excretory duct is effective to activate stem/progenitor cells in the submandibular gland.