Methods: The alteration of actin filaments was examinated by phalloidin, which specifically binds to F-actin to elucidate the role of cytoskeleton during regeneration of rat submandibular gland. In addition, α6β1- and α3-integrins were investigated immunohistochemically to analyze the relationship between the changes in the cytoskeleton and integrins. After 7 day's obstruction the regenerating glands were collected at days 0, 1, 3, 7, 11 and 14 after duct release to study regeneration.
Results: F-actin reactions were strongly observed at the apical regions of duct-like structures at days 3-7. As acinar cells differentiate, F-actin reactions were observed at the cortical site of mature cells. Strong labeling of α3-integrin was detected at the apical and lateral regions of duct-like structures during regeneration. The α6β1- integrin was expressed strongly in the maturing acinar cells during the early stage of regeneration. The double immunostains of α6β1- and α3-integrins revealed that at day3, α3-integrins were observed at immaturing acinar cells, and α6β1-integrins at more mesial site than α3-integrins.
Conclusions: These findings suggest that the localization of α3-integrin and the alteration of actin cytoskeleton affect cells polarization and differentiation, and α6β1-integrin is involved in the differentiation of the acinar cells during regeneration of rat submandibular gland.
Keywords: Cytoskeleton, Oral surgery, Salivary dysfunction and Salivary glands