Male Astronauts May Be at Risk of Erectile Dysfunction in Space
- NASA
On Earth, erectile dysfunction - the inability to establish and maintain an erection - affects more than half of men between 40 and 70 years old.
The effects of space exploration could therefore be an important consideration for male astronauts, especially if the condition persists in the long term.
Over four weeks, the authors of the new study exposed 86 adult male rats to either hindlimb unloading, an experimental way of simulating weightlessness by lifting them up by their tails so that they are suspended with their head down at a 30 degree angle, or a control where they were able to touch the floor.
Hindlimb unloading mimics two of the major physiological effects of low gravity, namely that the animals don't bear weight so there is no resistance on their muscles and bones, and it mimics shifts in body fluid and pressure that happen in an absence of gravity, La Favor said.
At the same time, using the ground-based GCR simulator at the NASA Space Radiation Laboratory in New York, the rats were exposed to one dose of either low or high amounts of cosmic radiation.
Around 12 to 13 months later, the authors euthanized the mice and extracted samples from the corpus cavernosum, the erectile tissue of the penis and the internal pudendal artery, the major artery that regulates the flow of blood into the penis during an erection.
They discovered that GCR, and to a lesser extent weightlessness, impaired the function of both types of tissue mainly by increasing oxidative stress - when there is a build up of free radicals in the body which can damage cells.
Follow-up experiments, however, showed that it was possible to counteract some of the effects caused by GCR using certain types of antioxidants.
The study only considered the health effects of GCR and weightlessness following a long recovery period, so it is possible that the short-term effects could be more severe, the authors wrote in the paper.
