HZE radiation effects for hereditary renal carcinomas

Area of Science:

• Space radiation research
• Experimental oncology
• Radiation biology

Background:

• Eker rats serve as a model for hereditary renal carcinoma (RC), exhibiting Mendelian dominant inheritance of cancer predisposition.
• Understanding the effects of space radiation is crucial for astronaut health and long-term space missions.

Purpose of the Study:

• To investigate the impact of simulated space radiation (heavy ions) on carcinogenesis in Eker rats.
• To estimate the relative biological effectiveness (RBE) of carbon and iron ions compared to X-rays.

Main Methods:

• Eker rats were exposed to carbon (C) and iron (Fe) ions, and X-rays at doses of 1, 2, and 3 Gy on day 19 of gestation.
• Offspring were analyzed at 8 weeks for organ weights and tumor development.
• Dose-response relationships were used to calculate RBE values.

Main Results:

• Organ weights (thymus, lung, liver, spleen) showed no change at 1 Gy but decreased by 50% at 3 Gy.
• Kidney, brain, and testes were sensitive organs, with weights decreasing to ~80% at 1 Gy and ~40% at 3 Gy.
• Calculated RBE values were 1.1 for C-ion and 1.6 for Fe-ion.

Conclusions:

• Simulated space radiation exposure affects organ development and induces carcinogenesis in Eker rats.
• Iron ions demonstrated a higher RBE than carbon ions, indicating greater biological effectiveness.
• These findings contribute to understanding radiation risks in space exploration.