Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
Life Sci Space Res (Amst). 2023 May;37:78-87. doi: 10.1016/j.lssr.2023.03.008. Epub 2023 Mar 30.
Astronauts on missions beyond low Earth orbit will be exposed to galactic cosmic radiation, and there is concern about potential adverse cardiovascular effects. Most of the research to identify cardiovascular risk of space radiation has been performed in rodent models. To aid in the translation of research results to humans, the current study identified long-term effects of high-energy charged particle irradiation on cardiovascular function and structure in a larger non-rodent animal model.
At the age of 12 months, male New Zealand white rabbits were exposed to whole-body protons (250 MeV) or oxygen ions (O, 600 MeV/n) at a dose of 0 or 0.5 Gy and were followed for 12 months after irradiation. Ultrasonography was used to measure in vivo cardiac function and blood flow parameters at 10- and 12-months post-irradiation. At 12 months after irradiation, blood cell counts and blood chemistry values were assessed, and cardiac tissue and aorta were collected for histological as well as molecular and biochemical analyses. Plasma was used for metabolomic analysis and to quantify common markers of cardiac injury.
A small but significant decrease in the percentage of circulating lymphocytes and an increase in neutrophil percentage was seen 12 months after 0.5 Gy protons, while O exposure resulted in an increase in monocyte percentage. Markers of cardiac injury, cardiac troponin I (cTnI) and N-Terminal pro-B-type Natriuretic Peptide were modestly increased in the proton group, and cTnI was also increased after O. On the other hand, metabolomics on plasma at 12 months revealed no changes. Both types of irradiation demonstrated alterations in cardiac mitochondrial morphology and an increase in left ventricular protein levels of inflammatory cell marker CD68. However, changes in cardiac function were only mild.
Low dose charged particle irradiation caused mild long-term changes in inflammatory markers, cardiac function, and structure in the rabbit heart, in line with previous studies in mouse and rat models.
在低地球轨道以外执行任务的宇航员将暴露于银河宇宙辐射下，人们担心其可能对心血管系统产生不良影响。大多数确定太空辐射对心血管风险的研究都是在啮齿动物模型中进行的。为了帮助将研究结果转化到人类身上，本研究在一种较大的非啮齿动物模型中确定了高能带电粒子辐射对心血管功能和结构的长期影响。
在 12 个月大时，雄性新西兰白兔接受全身质子（250 MeV）或氧离子（O，600 MeV/n）照射，剂量为 0 或 0.5 Gy，并在照射后 12 个月进行随访。超声心动图用于测量照射后 10 个月和 12 个月时的心脏功能和血流参数。照射后 12 个月时，评估血细胞计数和血液化学值，并收集心脏组织和主动脉进行组织学以及分子和生化分析。使用血浆进行代谢组学分析，并定量常见的心脏损伤标志物。
0.5 Gy 质子照射 12 个月后，循环淋巴细胞的百分比略有下降，中性粒细胞的百分比略有增加，而 O 暴露导致单核细胞的百分比增加。心脏损伤标志物肌钙蛋白 I（cTnI）和 N 末端 pro-B 型利钠肽（NT-proBNP）在质子组中略有增加，O 照射后也增加了。另一方面，12 个月时的代谢组学血浆无变化。两种类型的辐照都显示心脏线粒体形态改变和左心室炎症细胞标志物 CD68 蛋白水平增加。然而，心脏功能的变化仅为轻度。
低剂量带电粒子辐射导致兔心脏的炎症标志物、心脏功能和结构出现轻度的长期变化，与先前在小鼠和大鼠模型中的研究结果一致。
