ABSTRACT
Objective:To investigate the expression and correlation of Bcl-2 and Bax in the parotid gland after leading duct ligation in rats. Methods:Atrophy of the right parotid was induced by ligating the right main duct of 72 rats. Immunohistochemical labelling was performed to study the expression of Bcl-2 and Bax 1, 3, 5, 7, 14, 21, 30, 60, 90, 150 and 180 days after duct ligation. Results:7 d after duct ligation most acinar cells disappeared. The distribution of Bcl-2 and Bax protein in normal parotid was in cytoplasm with unifo-maity. Bcl-2 and bax higher expression was identified in the gland at all time points. The expression of Bcl-2 protein was significantly in-creased and reached the peak at 21 d after duct ligation. More Bax-positive acinar cells on day 3 were observed, then the expression of Bcl-2 and Bax protein was descended. Higher Bcl-2/Bax ratio was identified at 1-21 d, then descended. Conclusion:The expression of Bcl-2 and Bax is associated with the atophy of the parotid glad after rat parotid duct ligation.
ABSTRACT
Objective:To investigate the histological changes of parotid gland after ligation and reopening of the main duct.Meth-ods:The right parotid main duct was ligated for 14 days and then reopened,the specimen were harvested at day 0,1,3,5,7,10,14 and 21 after reopening(n=5 )respectively.By HE staining and Morphology measurement,the morphological and volume fraction changes of acinus,duct and mesenchyma were observed and measured.Results:The parotid gland atrophied significantly 14 days af-ter the duct ligation.From day 3 after duct reopening,the acinar volume fraction continued to increase,both the duct and the mesen-chymal tissue volume fraction continued to decrease significantly(P0.05).Conclu-sion:After reopening of the ligated main duct the atrophied parotid gland is able to regenerate to be normal.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the changes on the number and distribution of myoepithelial cells (MECs) during parotid gland regeneration.</p><p><b>METHODS</b>A total of 54 Wistar rats were divided into eight experimental groups and one normal control group, with six rats in each group. The right parotid ducts of the rats in the experimental groups were ligated for 14 days and then reopened. The parotid tissue specimens were harvested at days 0, 1, 3, 5, 7, 10, 14, and 21. The histological changes of the regenerating gland were examined using hematoxylin-eosin staining. Immunohistochemical labeling was also performed to investigate the changes in the number and distribution of MECs at different time points of parotid regeneration. Both the histological and immunohistochemical changes observed in the experimental groups were compared with those in the normal control group.</p><p><b>RESULTS</b>The parotid gland showed marked atrophy 14 days after ligation. Most acinar cells disap- peared, but the number of duct-like structures obviously increased. MECs apparently increased in number and were mainly located at the periphery of the duct-like structures. Three days after duct reopening, the number of acinar cells significantly increased and the duct-like structures significantly reduced. Meanwhile, MECs also decreased in number and were mainly located at the periphery of the newly formed acini and duct-like structures. The number of MECs noticeably decreased 3 and 5 days after duct reopening. At 14 days after duct reopening, the glandular structures and the number and distribution of MECs returned to normal compared with those in the normal control group.</p><p><b>CONCLUSION</b>The number and distribution of MECs returned to normal condition after parotid gland atrophy. Parotid regeneration mainly occurred within 5 days after duct reopening.</p>