Effects of X-ray and carbon-ion beam irradiation on pathological cardiac remodeling in mice

The objective of this study was to evaluate the effects of X-ray and carbon-ion (C-ion) beam irradiation on murine hearts under both normal and pathological conditions. Pathological cardiac hypertrophy was induced in mice by transverse aortic constriction (TAC) surgery. The control and TAC groups were irradiated with 30 Gy of X-rays or C-ion beams. Cardiac function was assessed every two weeks using echocardiography. Fibrosis, cardiomyocyte hypertrophy and Nppb expression were evaluated 8 weeks post-TAC. Irradiation had a limited effect on heart weight and function in control mice, although Nppb levels were elevated. TAC mice exhibited functional decline and increased fibrosis, which were improved by C-ions but not X-rays. Irradiation improved cardiac function and fibrosis in mice with heart failure, suggesting potential cardioprotective benefits. At the same physical dose, C-ion irradiation showed a trend toward improved cardiac function and reduced fibrosis; however, these differences were not significant compared with X-rays.