Cardiovascular adaptation to spaceflight.

This article reviews recent flight and ground-based studies of cardiovascular adaptation to spaceflight. Prominent features of microgravity exposure include loss of gravitational pressures, relatively low venous pressures, headward fluid shifts, plasma volume loss, and postflight orthostatic intolerance and reduced exercise capacity. Many of these short-term responses to microgravity extend themselves during long-duration microgravity exposure and may be explained by altered pressures (blood and tissue) and fluid balance in local tissues nourished by the cardiovascular system. In this regard, it is particularly noteworthy that tissues of the lower body (e.g., foot) are well adapted to local hypertension on Earth, whereas tissues of the upper body (e.g., head) are not as well adapted to increase in local blood pressure. For these and other reasons, countermeasures for long-duration flight should include reestablishment of higher, Earth-like blood pressures in the lower body.

[1]  J B Charles,et al.  Cardiovascular deconditioning during space flight and the use of saline as a countermeasure to orthostatic intolerance. , 1985, Aviation, space, and environmental medicine.

[2]  C S Leach,et al.  The endocrine and metabolic responses to space flight. , 1983, Medicine and science in sports and exercise.

[3]  C. Kilo,et al.  Regional variations in the width of the basement membrane of muscle capillaries in man and giraffe. , 1971, The American journal of pathology.

[4]  A. Hargens Fluid shifts in vascular and extravascular spaces during and after simulated weightlessness. , 1983, Medicine and science in sports and exercise.

[5]  S. Mulvagh,et al.  Echocardiographic Evaluation of the Cardiovascular Effects of Short‐Duration Spaceflight , 1991, Journal of clinical pharmacology.

[6]  R T Whalen,et al.  Lower body negative pressure to provide load bearing in space. , 1991, Aviation, space, and environmental medicine.

[7]  A R Hargens,et al.  Transcapillary fluid shifts in tissues of the head and neck during and after simulated microgravity. , 1991, Journal of applied physiology.

[8]  A R Hargens,et al.  Supine exercise during lower body negative pressure effectively simulates upright exercise in normal gravity. , 1994, Journal of applied physiology.

[9]  A R Hargens,et al.  Dynamic leg exercise improves tolerance to lower body negative pressure. , 1994, Aviation, space, and environmental medicine.

[10]  A. Crenshaw,et al.  Intramuscular pressure and electromyography as indexes of force during isokinetic exercise. , 1993, Journal of applied physiology.

[11]  B S Bennett,et al.  Short-duration spaceflight impairs human carotid baroreceptor-cardiac reflex responses. , 1992, Journal of applied physiology.

[12]  A. Hargens,et al.  Cerebral blood flow velocity in humans exposed to 24 h of head-down tilt. , 1993, Journal of applied physiology.

[13]  C S Leach,et al.  Influence of spaceflight on erythrokinetics in man. , 1984, Science.

[14]  D. E. Philpott,et al.  Morphological and biochemical examination of Cosmos 1887 rat heart tissue: Part I — ultrastructure , 1990, FASEB journal : official publication of the Federation of American Societies for Experimental Biology.

[15]  C. G. Blomqvist,et al.  Orthostatic intolerance after spaceflight. , 1996, Journal of applied physiology.

[16]  R. Millard,et al.  Gravitational haemodynamics and oedema prevention in the giraffe , 1987, Nature.

[17]  C. G. Blomqvist,et al.  Central venous pressure in space. , 1993, Journal of applied physiology.

[18]  C. G. Blomqvist,et al.  Central venous pressure in space. , 1996, The New England journal of medicine.

[19]  V. Ninane,et al.  Rib cage shape and motion in microgravity. , 1992, Journal of applied physiology.

[20]  S. Fortney Development of Lower Body Negative Pressure as a Countermeasure for Orthostatic Intolerance , 1991, Journal of clinical pharmacology.

[21]  O H Gauer,et al.  Venous pressure in man during weightlessness. , 1984, Science.

[22]  N Foldager,et al.  Central venous pressure in humans during short periods of weightlessness. , 1987, The Physiologist.

[23]  A R Hargens,et al.  Postural responses of head and foot cutaneous microvascular flow and their sensitivity to bed rest. , 1991, Aviation, space, and environmental medicine.

[24]  J B Charles,et al.  Cardiovascular Adaptation to Spaceflight , 1991, Journal of clinical pharmacology.

[25]  J. Levick,et al.  The effects of position and skin temperature on the capillary pressures in the fingers and toes , 1978, The Journal of physiology.