小香猪放射性创面模型的制备

Establishment of irradiation wound model in adult Bama miniature pigs

目的制备一种小香猪放射性创面的动物实验模型并观察病理变化，以期用于开展放射性创面相关疾病的在体研究。方法选取8头成年巴马小香猪，按随机数字表法均分为正常对照组、实验组，实验组又分为10，20及30Gy组，每组16个创面。实验组采用X射线直线加速器进行照射，并在照射部位使用打孔器制备边长4cm的全层皮肤缺损，制备小香猪放射性创面模型。每隔1周观察创面愈合情况；采用RT-PCR检测35d各组创面组织肿瘤坏死因子-α（TNF-α）和转化生长因子-β（TGF-β）的表达变化；Westernblot方法检测35d后各组创面组织血小板-内皮细胞黏附分子（CD31）和Ⅰ型胶原的表达变化；HE染色观察35d后各组创面组织病理学变化。结果正常皮肤创面在35d达到愈合状态，但20Gy组和30Gy组在63d仍未愈合，随着射线剂量增加创面愈合程度逐渐减弱。RT—PCR检测结果显示，TNF-αmRNA表达水平正常对照组为0．315±0．007，10Gy组为0．984±0．211，20Gy组为1．140±0．088，30Cy组为0．471±0．030；TGF-βmRNA表达水平正常对照组为0．402±0．018，10Gy组为1．707±0．147，20Gy组为1．933±0．078，30Gy组为0．968±0．084。与正常对照组比较，20Gy组TNF-α和TGF-βmRNA表达水平明显升高（P〈0．05）。Westernblot检测结果显示，20Gy组与正常对照组比较，CD31和Ⅰ型胶原的表达均受到抑制（P〈0．05）。HE染色结果显示，35d后20Gy组创面组织上皮化和肉芽组织再生受到影响。结论经过20GyX射线局部照射后制备的小香猪皮肤全层缺损创面能真实有效地模拟放射性创面，可开展放射性创面相关疾病病理生理及治疗干预的在体实验研究。

Objective To establish experimental radioactive wound model in miniature pig and observe its pathological changes in order to carry out in vivo study of radioactive wound-related diseases. Methods According to the random number table, eight adult Bama miniature pigs were divided into four groups after being anesthetized： normal control and experiment groups exposed to 0, 10, 20 and 30 Gy respectively using the X-ray linear accelerator. Then a puncher was use to prepare full-thickness skin defects （4 cm in length ） in the irradiation site. Wound samples were collected every other week to observe wound healing. RT-PCR was used to measure expressions of tumor necrosis factor （TNF）-α and transforming growth factor （TGF）-β in wound tissues 35 days after irradiation. At the same time, Western blot was utilized to detect expressions of CD31 and collagen Ⅰ . HE staining was applied toobserve histopathological changes of the radioactive wound. Results Skin wounds in normal control group healed in 35 days. Whereas in 20 and 30 Gy experiment groups, the wounds were not healed in 63 days and the healing rate was gradually weakened with the irradiation dose increasing. Expression ratio of TNF-α mRNA was 0. 315 ±0.007 in normal control group, 0. 984 ±0.211 in 10 Gy experiment group, 1. 140 ± 0. 088 in 20 Gy experiment group, and 0. 471 ± 0. 030 in 30 Gy experiment group. Expression ratio of TGF-β mRNA was 0. 402 ± 0.018 in normal control group, 1. 707 ± 0. 147 in 10 Gy experiment group, 1. 933 ± 0. 078 in 20 Gy experiment group, and 0. 968 ± 0. 084 in 30 Gy experiment group. Expressions of TNF-α and TGF-β mRNA were significantly increased in 20 Gy experiment group compared to normal control group （ P 〈 0. 05 ）. Expressions of CD 31 and Collagen I protein were inhibited in 20 Gy experiment group compared to normal control group （ P 〈 0.05 ）. Epithelialization and granulation tissue regeneration in 20 Gy experiment group were impaired. Conclusion An irradiation wound model in Bama miniature pigs can be efficiently and effectively simulated using the 20 Gy X-ray irradiation combined with full-thickness skin defect, and can be used to study the pathophysiology and therapeutic intervention of radioactive wound-related diseases in vivo.