UF Researcher Launches Experiments On Space Shuttle Columbia

June 19, 1996

GAINESVILLE — Scientists hope two groups of rats being launched into space Thursday (6/20) on the shuttle Columbia will shed light on a unique 20th century phenomenon — bone loss in astronauts.

The rats are part of a study being conducted by University of Florida veterinary scientist Tom Wronski, one of 21 scientists whose research will be conducted during the 16-day shuttle mission.

Wronski is testing the theory that excessive amounts of hormones called corticosteroids contribute to bone loss in astronauts after long-term space flight. To do this, Wronski sent two groups of rats into space as part of the National Aeronautic and Space Administration’s Life and Microgravity Spacelab (LMS) mission. Two additional groups of rats will be studied on the ground under standard laboratory conditions.

Using the rats as an animal model, Wronski will examine how corticosteroids, hormones secreted by the adrenal glands in response to stress, may play a role in space-related bone loss in astronauts.

“It’s well established that people experience accelerated loss of bone during lengthy excursions in outer space,” Wronski said. “Most assume this is due to weightlessness. However, there is the possibility that corticosteroids may contribute to bone loss.”

One in-space and one on-ground group of rats will have their adrenal glands removed surgically and will undergo implantation of corticosteroid pellets.

“By implanting these pellets, we’re giving these rats (which lack adrenal glands) normal corticosteroid levels,” Wronski said. “The other group of rats with intact adrenal glands, on the other hand, will have elevated levels during space flight.”

If corticosteroids can be kept at a normal level, this may protect against bone loss during space flight, Wronski said. Such a finding could lead to improved treatment strategies to protect the astronauts.

While on board the shuttle, the rats will be housed in a self-contained module that provides food, water, ventilation, lighting and an internal waste management system that isolates the animals from their waste. During the mission, the crew will check the health of the rodents daily, viewing them through a clear window in the top of each module and noting their activity and physical fitness. The crew also will resupply drinking water in each module.