During space missions, exposure to microgravity and galactic cosmic radiation can cause potentially irreversible kidney problems in astronauts.
- A new study shows that damage from galactic cosmic radiation and microgravity could be “catastrophic” to the human body.
- In detail, space conditions could “remodel” the kidneys and cause a narrowing of the tubules, responsible for the precise regulation of calcium and salt balance.
- Kidneys of mice exposed to radiation equivalent to two-and-a-half-year missions to Mars suffered permanent damage and loss of function.
Would astronauts’ kidneys survive a round trip to Mars? This is the question that researchers at University College London (England) have asked themselves. “Deep space missions are planned for this decade. Yet the health consequences of exposure to microgravity and galactic cosmic radiation during multi-year flights on vital visceral organs, such as the kidney, are largely unexplored.”
Spaceflight: Kidney remodeling narrows tubules
To answer their question, the scientists carried out a study published in the journal Nature Communications. They conducted biomolecular, physiological and anatomical assessments using data from 20 previous research projects. This included samples from more than 40 low-Earth orbit space missions involving humans and mice, most of which were destined for the International Space Station, as well as 11 space simulations involving mice and rats. Seven of these simulations involved rodents exposed to simulated doses of galactic cosmic radiation equivalent to one-and-a-half and two-and-a-half-year missions to Mars, mimicking spaceflight beyond Earth’s magnetic field.
The results showed that the kidneys of humans and animals were being “remodeled” by space conditions. After less than a month in space, the team observed specific renal tubules, responsible for fine-tuning calcium and salt balance, showing signs of shrinkage. This is likely one of the main contributors to kidney stone formation. They say the likely cause of this phenomenon is microgravity rather than galactic cosmic radiation. “However, further research is needed to determine whether the interaction of microgravity and galactic cosmic radiation can accelerate or exacerbate these structural changes.”
“Even if an astronaut could go to Mars, he might need dialysis upon return.”
Another alarming finding: the kidneys of mice exposed to radiation equivalent to two-and-a-half-year missions to Mars suffered permanent damage and loss of function. “If we don’t develop new ways to protect the kidneys, I would say that even if an astronaut could go to Mars, they might need dialysis when they return. We know that kidneys are slow to show signs of radiation damage, by the time it becomes obvious it will probably be too late to prevent failure, which would be catastrophic for the chances of mission success,” said Keith Siewlead author of the work.