活血化瘀药物防治放射性肺损伤的实验研究

目的观察活血化瘀药物对小剂量重复照射下不同时相大鼠肺组织病理学改变和肿瘤坏死因子-α（TNF-α）、转化生长因子-β（TGF-β）表达，探讨其防治放射性肺损伤的作用机制。方法130只SD雌性大鼠随机分为单纯照射组（60只）、中药治疗组（60只）和空白对照组（10只）用直线加速器对单纯照射组和中药治疗组大鼠右肺进行照射，3Gy／次，2次／周，累积剂量最高为30Gy，分别于照射开始后第1、3、5、8、12、26周共6个时间点，两组各随机处死10只大鼠，取材切片，行HE和免疫组化染色，观察大鼠肺组织病理改变和TNF-α和TGF-β的表达。结果单纯照射组大鼠肺组织于照射第5周急性放射性肺炎最重，第26周肺纤维化明显；不同时相TNF-α和TGF-β表达明显增强（P〈0．01），中药治疗组大鼠肺组织急性放射性肺炎反应轻微，后期纤维化不明显，TNF-α、TGF-β的表达较单纯照射组明显降低（P〈0．01）；结论在小剂量重复照射过程中，活血化瘀药物可抑制致炎因子和致纤维化因子的表达，减轻早期放射性肺炎的炎症反应。延缓放射性肺纤维化的进展，对放射性肺损伤具有防治作用。

Experimental Study on the Prevention and Treatment of Radiation Lung Injury by Blood-activating and Stasis-dissipating Drugs

OBJECTIVE: To observe the pathological changes and the expression of tumor necrosis factor alpha (TNF-alpha) and transforming growth factor beta (TGF-beta) in lung tissue of rats with radiation injury for exploring the mechanism of blood-activating and stasis-dissipating drugs in radiation injury prevention and treatment. METHODS: One hundred and thirty SD female rats were randomly allocated into the simple irradiation group (n=60), the TCM herbs treatment group (n=60) and the blank control group (n=10). The right lung of all rats except those in the blank control group were irradiated by linear accelerator, 3 Gy each time, twice weekly, the maximum accumulated dose being 30 Gy. Ten rats in the two groups were randomly sacrificed at each of the 6 time points (1, 3, 5, 8, 12 and 26 weeks after repeated irradiation), their lung was harvested out, sliced and dyed with HE stain. The histological changes, levels of TNF-alpha and TGF-beta expression in the lung tissue were then observed by immunohistochemical technique. RESULTS: The most serious acute radiation pneumonia was seen in the 5th week and pulmonary fibrosis was remarkable in the 26th week in the simple irradiation group, with the expressions of TNF-alpha and TGF-beta at different time phases enhanced significantly (P < 0.01). While in the TCM herbs treatment group, the pneumonia was milder, pulmonary fibrosis in late stage was not so obvious, and the expressions of TNF-alpha and TGF-beta significantly lower than those in the simple irradiation group (P < 0.01). CONCLUSION: Blood-activating and stasis-dissipating drugs can inhibit expression of inflammation-inducing factors and fibrosis-inducing factors to lessen the inflammatory reaction of early radiation pneumonia, prolong the progression of radiation lung fibrosis, showing preventive and treating action on radiation lung injury.