Effects of low-dose oxygen ions on cardiac function and structure in female C57BL/6J mice

Effects of Simulated 5-Ion Galactic Cosmic Radiation on Function and Structure of the Mouse Heart

“…However, male CD1 mice exposed to GCRsim showed a significant increase in collagen percentage in the heart, although this was not seen in female CD1 mice. While Yan et al demonstrated cardiac fibrosis after proton and 56 Fe (150 mGy, 1 GeV/n) exposure in male C57BL/6NT mice [ 7 ], our previous studies using 16 O (100 mGy-1 Gy, 600 MeV/n) in male and female C57BL/6J mice did not result in increased cardiac collagen deposition [ 1 , 6 ]. Overall, these studies demonstrate the importance of studying the effects of simulated GCR in multiple animal models and animal strains, since they may have different outcomes.…”

“…In addition, there was a significant increase in the density of the capillary network in the myocardium of these irradiated female CD1 mice, which may be explained at least in part by the decrease in their left ventricular mass. Our previous studies using single ion beams have shown changes in cardiac ejection fraction and fractional shortening in male C57BL/6J mice [ 1 , 2 ] but not in female C57BL/6J mice [ 6 ], indicating that sex differences in radiation response in the heart can occur. Indeed, there is an increasing number of studies demonstrating sex differences after GCR exposure [ 6 , 38 , 39 ].…”

“…Our previous studies using single ion beams have shown changes in cardiac ejection fraction and fractional shortening in male C57BL/6J mice [ 1 , 2 ] but not in female C57BL/6J mice [ 6 ], indicating that sex differences in radiation response in the heart can occur. Indeed, there is an increasing number of studies demonstrating sex differences after GCR exposure [ 6 , 38 , 39 ]. However the exact mechanisms of how GCRsim effects the cardiovascular system of males and females differently remains unclear.…”

“…Since few astronauts have left LEO thus far, the health risks of long-distance space travel are estimated from ground-based models or from missions on the International Space Station. Previous ground-based studies investigating the effects of simulated space radiation on the cardiovascular system have utilized high atomic weight, high energy (HZE) radiation in the form of single or fractionated exposures to one ion [ 1 , 2 , 3 , 4 , 5 , 6 ]. These previous rodent studies have shown alterations in cardiac function [ 7 ], cardiac inflammation [ 4 ], and vascular stiffness and endothelial dysfunction [ 8 ].…”

“…Recent studies have also demonstrated that HZE exposure resulted in cellular changes that could lead to cardiovascular disease [ 9 , 10 ]. Our previous studies utilizing single ion beams from NASA’s Space Radiation Laboratory (NSRL) have demonstrated minor changes in cardiac form and function [ 1 , 2 ], and the cardiac changes may be different between sexes [ 6 ]. Since the radiation environment in deep space consists of multiple ions at varying fluences, it is important to determine the health risks associated with multi-ion exposures.…”