Vestibular system contributes human arterial blood pressure control upon gravitational change
- Paper number
IAC-05-A1.4.03
- Author
Ms. Chihiro Awazu, Fukui University, Japan
- Coauthor
Mr. Taro Gotoh, Japan
- Coauthor
Ms. Tomoko Matsuda, Japan
- Coauthor
Prof. Hironobu Morita, Japan
- Coauthor
Dr. Kunihiko Tanaka, Japan
- Year
2005
- Abstract
Recent studies from our laboratory demonstrated the important role of vestibular system in arterial pressure regulation during gravitational change in conscious rats. The goal of the present study was to examine whether the vestibular system has an important role in arterial pressure regulation in human. The experiments were conducted on young adult volunteers with measuring arterial pressure during gravitational change induced by parabolic flight. To disturb the intact input to vestibular system, galvanic vestibular stimulation (GVS) was applied, and the arterial pressure responses were compared between with and without GVS. Without GVS, arterial pressure increased at the onset of microgravity, then recovered to the 1 G level while microgravity condition continued. GVS itself had no effect on arterial pressure at rest. However, in subjects with GVS, the increase in arterial pressure was abolished and it decreased by 10 mmHg during 20 s microgravity condition. These results indicate that the vestibular system in human plays important role in controlling arterial pressure during microgravity. It is known that the vestibular system is highly plastic and adapts to the microgravity environment during spaceflight. Thus, it is speculated that plastic alternations of the vestibular system may be partly responsible for cardiovascular deconditioning after spaceflight.
- Abstract document