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Record Details

Record 43 of 718
Neuroendocrine and Immune System Responses with Spaceflights
External Online Source: doi:10.1097/00005768-199608000-00009
Author and Affiliation:
Tipton, Charles M.(NASA Ames Research Center, Moffett Field, CA United States)
Greenleaf, John E.(NASA Ames Research Center, Moffett Field, CA United States)
Jackson, Catherine G. R.(NASA Ames Research Center, Moffett Field, CA United States)
Abstract: Despite the fact that the first human was in space during 1961 and individuals have existed in a microgravity environment for more than a year, there are limited spaceflight data available on the responses of the neuroendocrine and immune systems. Because of mutual interactions between these respective integrative systems, it is inappropriate to assume that the responses of one have no impact on functions of the other. Blood and plasma volume consistently decrease with spaceflight; hence, blood endocrine and immune constituents will be modified by both gravitational and measurement influences. The majority of the in-flight data relates to endocrine responses that influence fluids and electrolytes during the first month in space. Adrenocorticotropin (ACTH), aldo-sterone. and anti-diuretic hormone (ADH) appear to be elevated with little change in the atrial natriuretic peptides (ANP). Flight results longer than 60 d show increased ADH variability with elevations in angiotensin and cortisol. Although post-flight results are influenced by reentry and recovery events, ACTH and ADH appear to be consistently elevated with variable results being reported for the other hormones. Limited in-flight data on insulin and growth hormone levels suggest they are not elevated to counteract the loss in muscle mass. Post-flight results from short- and long-term flights indicate that thyroxine and insulin are increased while growth hormone exhibits minimal change. In-flight parathyroid hormone (PTH) levels are variable for several weeks after which they remain elevated. Post-flight PTH was increased on missions that lasted either 7 or 237 d, whereas calcitonin concentrations were increased after 1 wk but decreased after longer flights. Leukocytes are elevated in flights of various durations because of an increase in neutrophils. The majority of post-flight data indicates immunoglobulin concentrations are not significantly changed from pre-flight measurements. However, the numbers of T-lymphocytes and natural killer cells are decreased with post-flight conditions. Of the lymphokines, interleukin-2 production, lymphocyte responsiveness, and the activity of natural killer cells are consistently reduced post-flight. Limited head-down tilt (HDT) data suggest it is an effective simulation model for microgravity investigations. Neuroendocrine and pharmacological countermeasures are virtually nonexistent arid should become high priority items for future research. Although exercise has the potential to be an effective countermeasure for various neuroen-docrine-immune responses in microgravity, this concept must be tested before flights to Mars are scheduled.
Publication Date: Jan 01, 1996
Document ID:
20000073392
(Acquired Aug 04, 2000)
Subject Category: AEROSPACE MEDICINE
Document Type: Reprint
Publication Information: Medicine and Science in Sports and Exercise (ISSN 0195-9131); 988-998
Publisher Information: American College of Sports Medicine, United States
Financial Sponsor: NASA Ames Research Center; Moffett Field, CA United States
Organization Source: NASA Ames Research Center; Moffett Field, CA United States
Description: 11p; In English
Distribution Limits: Unclassified; Publicly available; Unlimited
Rights: Copyright
NASA Terms: BLOOD PLASMA; COUNTERMEASURES; ENDOCRINE SYSTEMS; HYPOKINESIA; IMMUNE SYSTEMS; IN-FLIGHT MONITORING; MEASURING INSTRUMENTS; MICROGRAVITY; PHYSIOLOGICAL RESPONSES; ADRENOCORTICOTROPIN (ACTH); ALCOHOLS; ARID LANDS; DIURETICS; ELECTROLYTES; HORMONES; INSULIN; LEUKOCYTES; VASOCONSTRICTOR DRUGS; SPACE FLIGHT
Availability Source: Other Sources
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