Histological Changes During Atrophy And Regeneration Of Rat Parotid Gland

Objective:To establish Parotid gland injury model in Wistar rats by parotid duct ligation, we checked histological changes of parotid gland after ligation and reopening of parotid duct.Methods:Seventy adult male Wistar rats were used as sample, among them, the normal control group5, the experimental group65(including duct ligation group35and duct reopening group30). In the duct ligation group,the right parotid duct was bundling ligated with medical wire after anesthesia,the parotid gland specimen were harvested at days1,3,5,7,14,21,28.In the duct reopening group, the parotid duct was ligated for14days and reopened after removal of medical wire, the specimen were harvested at days1,3,5,7,14,21following the reopening of the parotid duct. All the specimen were prepared into tissue sections.By HE staining,Immunohistochemistry and Morphology measurement,we investigatd the morphological and volume fraction changes of acinus,duct and mesenchyma.Results:In the duct ligation group,compared with normal control group,from the3rd to28th days, the parotid gland showed marked atrophy, The acinar volume fraction continue to decrease significantly, both the duct’s and the mesenchymal volume fraction continue to increase significantly.(P<0.05). In the duct reopening group,compared with duct ligation14th day group, from the3rd to21th days after duct reopening, the parotid gland showed marked regeneration, The acinar volume fraction continue to increase significantly, both the duct’s and the mesenchymal volume fraction continue to decrease significantly.(P<0.05). After14days of regeneration, there were no significant differences in volume fractions of acinas,ducts and mesenchyma,compared with normal control group (P>0.05).Conclusion: The parotid gland atrophied after the parotid duct ligation, and the parotid duct could be reopened after duct ligation for14days, then after duct reopening,the gland regenerated obviously. The parotid gland was capable of regenerating to essentially normal after14days of duct reopening.