Autumn Pennington, an undergraduate exercise science student at Marshall University, and her faculty advisor, Dr. Kumika Toma, presented their research to the NASA American Society for Gravitational and Space Research (ASGSR) conference in Baltimore earlier this month.
Pennington’s study, titled “Sex, Age, and Exercise Effects on Bone Density and Muscle Mass in Rats,” received a score of 38 out of 40 from the judges presiding over the conference presentations.
Pennington presented a part of her research exploring the differences between male and female rats in terms of how exercise affects their bone density and muscle mass. Exercise stimulates mineral deposits to the bone where muscles are attached, and Pennington theorized that this would happen at different rates in male and female rats. She analyzed the weight of leg muscle and the bone mineral density of leg bones from old male and female rats taken from a space-flight simulation experiment, and then compared sex differences between the male and female specimens.
Pennington discovered that old female rats exhibited greater muscle mass and bone density than male rats, suggesting that estrogen provides a protective effect on muscle mass and bone density during aging. Losses of muscle mass and bone mineral density are serious concerns among astronauts due to low-gravity conditions. Pennington’s finding provides insight into possible long-lasting estrogen effects that may protect bone and muscle mass after menopause. Pennington’s research was done in collaboration with Dr. Habiba Chirchir, an assistant professor of biological sciences.
Toma is an associate professor of exercise science. Toma’s NASA-funded research, titled “A New Modification of HLS for Heavier and Active Rats,” developed and tested a novel modification to the common animal model to simulate space flight. Her research method uses a 3D-printed support system. For the space-flight research community, this method has many benefits.
Minimizing the number of rodents required for research and minimizing stress on rodents are best practices for animal welfare. In addition, this method is the first animal model to simulate in-flight exercise, which will enable further investigation into the effects of long-term flight on the musculoskeletal system and countermeasures to promote astronaut health. The research was conducted in collaboration with Dr. Steven Leigh, an associate professor of biomechanics in the School of Kinesiology and Dr. Michael Hambuchen, an assistant professor in the School of Pharmacy.