The Study On The Function Of Blood-cooling And Detoxicating Drugs In Preventing Early Radiation Pulmonary Injury

ObjectiveTo establish the model of radiation-induced lung injury simulating the radiation methods in clinical. And to observe the pathological signs and the dynamic change of cell factor in the model caused by multiple low dose exposure with pathology and molecular biology methods. Then to observe the function of blood-cooling and detoxicating drugs in early radiation-induced lung injury, and study it's mechanism.Methods160 wistar rats are divided randomly into control group, once high dose exposure group, multiple low dose exposure group and treatment group (40 rats each group). The rats in treatment group are treated with traditional Chinese drug by gastrogavage o.d. one week before radiation. At the same time, other rats are gastrogavaged with 9% NS. Rats in once high dose exposure group are once radiated at a dose of 30 Gy. The rats in multiple low dose exposure group and treatment group are radiated at a dose of 3 Gy twice a week, total 30 Gy. 8 rats in every group are chosen randomly and killed on the 3rd, 5th, 8th, 12th and 26th week. Then to observe the histological change of lungs stained with HE and measure TGF- β ,TNF- a ,IL-6 and bFGF in every groups using Image pro plus4.5 after immunohistochemical stain. At last, to analyze statistically the result using STATA 7.0.Results1. Typical signs of radiating pneumonia and lung fibrosis are observed in oncehigh dose exposure group and multiple low dose exposure group. In addition, there is no significent difference between two groups about TGF- P ,TNF- a ,IL-6 andbFGF(P>0. 05).2. TGF- P ,TNF- a ,IL-6 and bFGF were expressed lowly in rats in control group, and higher expression in two exposure group compared with control group (P<0. 05). The peak time of every cell factor is different.3. Slight syndrom of acute inflammation was observed in treatment group. And the attack rate of lung fibrosis and cell factor in rats of treatment group is lower apparently than exposure group (P<0. 05).Conclusions1. The rat model of radiation pulmonary injury can be established successfully by multiple low dose exposure. It has lots of merits, such as lower rate of death (P<0. 05) ,more integrity, good practicability.2. During the process of radiation pulmonary injury, cell factors interact to induce in common the disease.3. Applying blood-cooling and detoxicating drugs early may ameliorate symptom of radiation pulmonary injury, prevent radiation pneumonia, relieve the pulmonary fibrosis so that to prevent or release radiation pulmonary injury.4. The blood-cooling and detoxicating drugs can restrain the expression of TGF-P ,TNF- oc ,IL-6 and bFGF (P<0. 05). It is seemly the reason why the drugs maylessen the inflammation, relieve the pulmonary fibrosis and prevent early radiation pulmonary injury.