During deep space missions, astronauts are exposed to high levels of galactic cosmic radiation (GCR) and microgravity, which are associated with an increased risk of oxidative stress and endothelial dysfunction. Oxidative stress and endothelial dysfunction are causative factors in the pathogenesis of erectile dysfunction, although the effects of spaceflight on erectile function have been unexplored.
A new study aims to determine the effects of simulated spaceflight and long-term recovery on tissues critical for erectile function, the distal internal pudendal artery (dIPA), and the corpus cavernosum (CC).
The study involved 86 adult male Fisher-344 rats. They were randomized into six groups and exposed to 4-weeks of hindlimb unloading (HLU) or weight-bearing control and sham or simulated GCR at the ground-based GCR simulator at the NASA Space Radiation Laboratory.
Following a 12–13-month recovery, ex vivo physiological analysis of the dIPA and CC tissue segments revealed differential impacts of HLU and GCR on endothelium-dependent and -independent relaxation that was tissue type specific.
These aspects of spaceflight can have a deleterious impact on vascular tissues associated with erectile dysfunction, even after a prolonged time of recovery, according to simulation studies conducted on male rats.
Relatively low doses of galactic cosmic radiation and, to a lesser extent, simulated weightlessness cause vascular changes, mostly through increased oxidative stress. Different antioxidant treatments may mitigate some of these effects.
Corresponding author Justin D. La Favor, Ph.D., of Florida State University, said, “With manned missions to outer space planned for the coming years, this work indicates that sexual health should be closely monitored in astronauts upon their return to Earth.”
“While the negative impacts of galactic cosmic radiation were long-lasting, functional improvements induced by acutely targeting the redox and nitric oxide pathways in the tissues suggest that the erectile dysfunction may be treatable.”
Journal Reference:
- Manuella R. Andrade, Tooyib A. Azeez et al. Neurovascular dysfunction associated with erectile dysfunction persists after long-term recovery from simulations of weightlessness and deep space irradiation. The FASEB Journal. DOI: 10.1096/fj.202300506RR