Transforming Growth Factor-β₁(TGF-β₁) And Tumor Necrosis Factor-α (TNF-α) Expression In C57/BL Mice After Lung Radiation With Different Dose At Different Time And Relation Between Them And Radiation Injury Of Lung

Objective To investigate expression of transforming growth factor- 1(TGF-1) and tumor necrosis factor- a (TNF- a ) in male C57/BL mice after lung radiation with different radiation doses(6Gy or 10Gy) in different phases. We wanted to study the relation between them and radiation injury of lung,and those factors which influence radiation-induced lung injury. Methods Using male C57/BL mice, we radiated their right lungs with 6Gy or 10Gy(15MeV electron beam).Some other mice of 10 were taken to be control group(which were not be radiated). After radiation , we killed 2-5 mice in different groups and took their blood and right lungs at 36-hour,7-day,15-day,30-day,40-day. Serum was obtained by centrifugation of blood at 4000r/min for 5 minutes.The expression of transforming growth factor- 1 and tumor necrosis factor- a were evaluated with ELISA technique. We observed the histological changes of their right lungs stained with HE from 36 hours up to 40 days after right thorax radiation. Results After radiation,the condition of expression of TGF- 1:The average serum TGF- 1 level in mice which being radiated with6Gy was higher than the level of control group, after being radiated for 7days the average serum TGF- level got down to the normal level. The average serum TGF- 3 i level in mice which being radiated with lOGy was lower than the level of control group after being radiated for 36 hours, after being radiated for 7days or 15 days , 30days,40days,the average serum TGF- J3 , level in mice which being radiated with lOGy was higher than the level of control group.The results of analysis of variance :there was obvious difference among the second groups(P<0.05);there was not obvious difference among the factors of time(P>0.05);there was obvious difference among the factors of radiation doses(P<0.05).The condition of expression of TNF- a :The average serum TNF- a level in mice which being radiated with 6Gy was higher than the level of control group after being radiated for 36 hours,after 7 days became even more higher.From 15 days to 30 days,it got down,but still higher than control group. The average serum TNF- a level in mice which being radiated with lOGy was not higher than the level of control group after 36 hours or 7days.After radiation for 15 days,30 days540 days, the average serum TNF- a level was higher than control group.The results of analysis of variance :there was obvious difference among the second groups,the factors of time, the factors of radiation doses, (P<0.05).Histological changes:Acute inflammatory changes of the lung can be seen in the group of 10Gy with HE stained. But it was not very serious.We didn't find obvious difference between the lung of those being radiated with 6Gy and which of control group.Conclusions The reason of radiation induced injury of the normal lung has many factors.There was some matter between the radiation dose and TGF- β1;and there was some matter among the radiation dose,the factor of time and TNF- α in the serum.TGF- β1and TNF- α in the serum occurred continue change in the early phase.