Since 1961, there have been more than 165 flights involving several hundred individuals who have remained in a space environment from 15 min to more than a year. In addition, plans exist for humans to explore, colonize, and remain in microgravity for 1000 d or more. This symposium will address the current state of knowledge in select aspects associated with the cardiovascular, fluid and electrolytes, musculoskeletal, and the neuroendocrine and immune systems. The authors will focus on responses, mechanisms, and the appropriate countermeasures to minimize or prevent the physiological and biochemical consequences of a microgravity environment. Since exercise is frequently cited as a generic countermeasure, this topic will be covered in greater detail. Models for simulated microgravity conditions will be discussed in subsequent manuscripts, as will future directions for ground-based research.
Submitted for publication February 1995.
Accepted for publication December 1995.
Address for correspondence: Charles M. Tipton, Ph.D., Department of Physiology, Ina Gittings Building, Room 24A, University of Arizona, Tucson, AZ 85721-0093.
Department of Physiology, University of Arizona, Tucson, AZ 85721-0093; and Gravitational Research Branch, NASA Ames Research Center, Moffet Field, CA 94035