Establishment And Evaluation Of Acute Radiation-induced Heart Disease On The Model Of Rat Caused By Different Single Dose Radiation

Objective: The study is designed to investigate the scientific,rationality and feasibility of acute radiation-induced heart disease caused by different single dose radiation in rats,and to discovery the effect of oxidative stress in radiation-induced heart disease.Methods: Forty SD male rats were randomly divided into normal group,5Gy group,10 Gy group,20 Gy group and 30 Gy group.The rats in each irradiation group were irradiated under the VARIN 21-EX linear accelerator at heart,the source skin distance:100cm,the dose rate:200c Gy / min,the radiation field: 2.0cm × 2.0cm.At the end of 1 week and 4 week after irradiation,4 rats in each group were drugged by intraperitoneal injection.And the data of left ventricular end-diastolic pressure(LVEDP),left ventricular systolic pressure(LVSP),rate of rise of left ventricular pressure(±dp/dtmax)were examined through BL-820 s biological function experiment system.The content of c Tn I in serum was measured by ELISA,the content of MDA and the activity of SOD were tested by thiobarbituric acid method(TBA)and xanthine oxidase method.After the rats were executed,the hearts were harvested for further analysis.HE and Masson staining to observe the edema,degeneration,inflammatory cell infiltration and myocardial fibrosis of rat cardiomyocytes.Results: After 1 week of irradiated,irradiation induced significant increase in c Tn I and MDA level(P <0.05)and significant decrease in SOD level(P <0.05),there were nosignificant difference in LVSP,LVEDP,±dp/dtmax.The comparison of the irradiation dose group showed that the c Tn I level increased with the irradiation dose,and the 20 Gy and 30 Gy groups were significantly higher than those in the 5Gy and 10 Gy groups(P <0.05),and the change between 20 Gy and 30 Gy was not obvious.The content of MDA was 30Gy> 20Gy> 10Gy(P <0.05),and the change between 5Gy and 10 Gy was not obvious.After 4 weeks of irradiated,there were significant differences in each group of c Tn I,SOD and MDA(P <0.05),and LVSP,LVEDP,±dp/dtmax decreased significantly in 20 Gy and 30 Gy groups(P <0.05),but there were no significant differences between 20 Gy and 30 Gy groups.The comparison of the irradiation dose group showed that the concentration of c Tn I and MDA increased with the irradiation dose,30Gy> 20Gy> 10Gy> 5Gy(P <0.05).The level of SOD in 20 Gy and 30 Gy groups was significantly higher than that in 5Gy and 10 Gy groups(P <0.05),and the change between 20 Gy and 30 Gy was not obvious.Pathological results showed that there were different degrees of acute radiation-induced heart disease in each irradiated group.Conclusion: 1、Different characteristics were existed in the model of each irradiated groups,a single 20 Gy irradiation can be a better assessment of acute radiation-induced heart disease.2、The mechanism of radiation cardiac injury is related to oxidative stress,but signal transduction pathway and the specific initiation factor needs to be further studied.