Linked Life Data

11537597

Source:http://linkedlifedata.com/resource/pubmed/id/11537597

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PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1997-10-4
pubmed:abstractText
The changes of hormones in plasma involved in the body fluid regulation were studied in human subjects during and after space flights in relation to redistribution of body fluids in the state of weightlessness. Since hypokinesia was used as a model for simulation of some effects of the stay in microgravity the plasma hormone levels in rats exposed to hypokinesia were also investigated. Plasma aldosterone values showed great individual variations during the first inflight days, the increased levels were observed with prolongation of space flights. The important elevation was found in the recovery period, however it was interesting to note, that in some cosmonauts with repeated exposure to space flight, the postflight plasma aldosterone levels were not elevated. The urine excretion of aldosterone was increased inflight, however in postflight period the decrease or increase were found in the first 1-5 days. The increase of plasma renin activity was observed in flight and postflight period. The rats were exposed to hypokinesia (forced restriction of motor activity) for 1, 7 and 60 days and urine was collected during last 24 hours. The animals were sacrificed and the concentration of electrolytes and of levels of corticosterone, aldosterone (A), ANF and plasma-renin activity (PRA) were determined in plasma. In urine excretion of sodium and potassium were estimated. An important increase of plasma renin activity and aldosterone concentration was found after short-term hypokinesia (1 day). These hormonal values appear to decrease with time (7 days) and are not significantly different from controls after long-term hypokinesia (60 days). A decrease of values ANF in plasma was observed after 1 and 7 days hypokinesia. After prolonged hypokinesia a decrease of sodium plasma concentration was observed. The excretion of sodium in urine was higher in long-term hypokinetic animals. There were no significant changes of plasma potassium levels in rats exposed to hypokinesia, however the urinary excretion of potassium was elevated. In rats exposed to hypokinesia for 7 and 60 days an increase of urine osmolality was observed. The results of hormone and electrolyte determination in plasma of cosmonauts after space flight and in experimental animals after hypokinesia suggested that in evaluation of relations between the changes of hormone levels and electrolyte in plasma and urine other factors like emotional stress working load; altered diurnal cycles should be considered in interpretation of homeostatic response of fluid and electrolyte metabolism to space flight conditions.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
S
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0094-5765
pubmed:author
pubmed:issnType
Print
pubmed:volume
27
pubmed:owner
NASA
pubmed:authorsComplete
Y
pubmed:pagination
51-4
pubmed:dateRevised
2005-11-16
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Changes of hormones regulating electrolyte metabolism after space flight and hypokinesia.
pubmed:affiliation
Slovak Academy of Sciences, Bratislava, CSFR.
pubmed:publicationType
Journal Article, Review