Hershey, Pa. -- On Sept. 26, when astronaut Shannon Lucid returns
from 188 days in space, she may wobble a bit when she takes her first steps
at Kennedy Space Center. And, she may have difficulty standing up.
Orthostatic intolerance, or difficulty in standing, is a condition that
afflicts at least 70 percent of returning astronauts. Their blood pressure
systems are thrown off by the weightlessness of space travel. It takes time
for the astronauts to readjust--especially following lengthy trips like
Lucid's.
"Earthlings aren't exactly built for space travel," said Lawrence
I. Sinoway, M.D., professor of medicine at Penn State's Milton S. Hershey
Medical Center. Sinoway is conducting NASA-funded research at Hershey in
which he studies the way the human body fares under the stress of space
travel.
In addition to orthostatic intolerance, most astronauts have puffy faces
and thin legs because body fluids tend to relocate to the upper body during
space flight.
Sinoway's medical studies will help NASA figure out how best to maintain
astronauts' health during lengthy space flights, including a possible trip
to Mars which would take two years round trip for a manned expedition. A
visit to the red planet could come early in the 21st century according to
NASA.
To simulate the effects of weightlessness on the body, Sinoway and his staff
of cardiology researchers are conducting a series of experiments in which
they confine healthy 20- to 40- year old men to bed for two weeks. The research
is part of a three-year NASA study to examine sympathetic nerve activity
during exercise--both before and after extended bed rest.
Sinoway tracks the movement of information from the nerves to the blood
vessels with a special technique called microneurography, an innovative
method that is used in only a handful of research centers. It involves the
insertion of tiny needles into nerves to obtain an electronic recording
of neural transmissions.
"We want to see if exercise turns on the nervous system more after
bed rest," says Sinoway, explaining that this will suggest that space
flight alters and exaggerates how the nervous system responds to stress
function. "We are also interested in finding out whether these subjects
fatigue more easily during exercise after bed rest. If this occurs, we will
try to improve this situation, using exercise conditioning."
Sinoway was recently named program director of the General Clinical Research
Center (GCRC) at Hershey. The GCRC was established by the National Institutes
of Health to create and sustain specialized institutional resources in which
clinical investigators can observe and study human physiology as well as
study and treat disease with innovative approaches. A satellite study center
of the GCRC has been established at the Noll Physiological Research Center,
College of Health and Human Development, at the University Park campus.
Another Penn State researcher, James A. Pawelczyk, assistant professor of
applied physiology at Noll Physiological Research Center, also studies the
physiology of the body during space travel. He was chosen by NASA to train
as one of four payload specialists for the Neurolab mission in 1998. Neurolab
is a dedicated life sciences mission on neuroscience research, a contribution
to the "Decade of the Brain," sponsored by NASA and the National
Institutes of Health.
Contacts:
Gail Brown (o) (717) 531-8606 e-mail: gxg14@psu.edu
Deborah S. Saline (o) (717) 531-8606