The Protective Mechanism Of Glabrous Sarcandra Herb For Radiation Damage On The Irradiated Parotid Glands Of The Miniature Pig

Objective:Explore to the influence of a single dose of15Gy gamma-rays on pathological damage,apoptosis and proliferation of parotid glands in the miniature pig and explore the protective effects of Glabrous Sarcandra Herb.Methods:(1)To establish the experimental animal model of radiation damaged minuture pig:Chose45miniature pig of Bama with the similar age and body weight as the experimental subject,they were randomly divided into normal control group, radiation control group and medicine radiation group,then each group was randomized divided into three parallel group numbered a,b and c. Glabrous Sarcandra Herb were administered to the medicine radiation group a week before exposure to the radiation, and equal physiological saline for the others. The radiation control group and the medicine radiation group were received a single dose of15Gy gamma-rays delivered to each parotid gland, the normal control group was received0Gy gamma-rays.On the10th day,40th day and90th day after irradiation,the parotid glands of miniature pigs were removed in anesthetic state,preserved with the10%formalin.(2)The parotid gland which fixed by formalin was treated with paraffin embedding and microtomy.The pathological damage was observed by HE immunostaining,the apoptosis was detected by TUNEL method, and the expression of PCNA was detected by immunohistochemistry technique.Results:We can see the pathomorphological changes of karyopyknosis,vacuolization, acinar atrophy, interstitial thickening, inflammatory cell infiltration et.al on parts of the parotid gland cell of the radiation control group and medicine radiation group.The changes become more obvious over time and the changes of the medicine radiation group was less obvious than the radiation control group. The apoptosis rate of the radiation control group and the medicine radiation group was higher than the normal control group on every time point, there were significant differences compared to the normal control group (P<0.01); and rasied to the hightest point on the10th day, then reduced gradually, there were significant differences between every two groups (P<0.01); the apoptosis rate of medicine radiation group was lower than the radiation control group on the10th day,there was significant differences between these two groups (P<0.01). The expression of PCNA of the radiation control group and the medicine radiation group was higher than the normal control group on every time point, there were significant differences compared to the normal control group (P<0.01); and rasied to the hightest point on the40th day, then reduced on the90th day,there were significant differences between every two groups P≤0.01); the expression of PCNA of the medicine radiation group was higher than the radiation control group on every time point, there were significant differences between these two groups (P<0.01)Conclution:(1) The pathology confirmed that a single dose of15Gy gamma-rays can induce the radiation damage on the parotid gland.(2) Ionizing radiation may damage the parotid gland by inducing the apoptosis of the acinar cell, and the body may repaire the damage through proliferation.(3) The use of the Glabrous Sarcandra Herb was contributed to reduce the apoptosis rate and promote proliferation of the parotid gland.