The Preliminary Study On The Regeneration Of Rat Atrophied Parotid Gland

Objective:To investigate the histological changes during regeneration of the rat parotid gland after atrophy induced by parotid duct ligation,and to analyze the expression and significance of PCNA(proliferating cell nuclear antigen)and P53 in the process of parotid gland recanalization.Method:Wistar rats were randomly divided into experimental group and control group.The experimental group'duct was ligated and then after 7 days(group A),14 days(group B),21 days(group C)was released.Parotid specimens were obtained at 0?1?3?5?7?10?14?21?28?60 and 90 days after releasing the duct(Marked as Ao……A90,B0……B90,C0……C90).Hematoxylin and Eosin(HE)staining was used to observe the histological changes.Immunohistochemistry and real-time PCR(Real-Time PCR,RT-PCR)and Western Blot were used to explore the expression of PCNA and P53 in parotid gland.Tunel fluorescence detection was used to observe apoptotic changes of parotid gland.Result:On the zero day of group A?groupB and group C,parotid acinar cells were atrophied and ducts were dilated.With the reperfusion processes,acinar cells and the proportion of ductal and acinar cells increased gradually to close to normal in group A and groupB,but not completely restored in group C.PCNA and P53 were high and gradually increased in early recanalization of group A and group B compared with the normal group(P<0.01).Then they reached the maximum value at A3?B5.With the time prolonged,acinar and duct gradually returned to normal morphology,while PCNA and P53 content gradually closed to the normal control group at A14?B21,but both unstable and did not reach the normal value in group C.Tunel fluorescence detection showed that the apoptotic cells in group A and group B gradually decreased and were closed to the normal value.The apoptotic cells in group C showed no obvious signs of recovery.Conclusion:Release the catheter after the ligation of the parotid duct in a certain period of time,the acinar regeneration could be restored to normal The expression of PCNA and P53 was closely related to the regeneration process of parotid gland after ligation the duct and recanalization the parotid gland.It suggested that PCNA and P53 may play an important role in the proliferation of parotid gland.