Document Detail


Catecholamine response during 12 days of high-altitude exposure (4, 300 m) in women.
MedLine Citation:
PMID:  9516178     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
We have previously demonstrated that acclimatization to high altitude elicits increased sympathetic nerve activity in men. The purpose of this investigation was to determine 1) whether women respond in a similar manner as found previously in men and 2) the extent to which menstrual cycle phase influences this response. Sixteen eumenorrheic women (age, 23.6 +/- 1.2 yr; weight, 56.2 +/- 4. 3 kg) were studied at sea level and during 12 days of high-altitude exposure (4,300 m) in either their follicular (F; n = 11) or luteal (L; n = 5) phase. Twenty-four-hour urine samples were collected at sea level and during each day at altitude. Catecholamines were determined by high-performance liquid chromatography with electrochemical detection. Compared with sea-level values, urinary norepinephrine excretion increased significantly during altitude exposure, peaking on days 4-6. Thereafter, levels remained constant throughout the duration of altitude exposure. The magnitude of this increase was similar between the F (138%) and L (93%) phase. Urinary epinephrine levels were elevated on day 2 of altitude exposure compared with sea-level values for both F and L subjects (93%). Thereafter, urinary epinephrine excretion returned to sea-level values, and no differences were found between F and L subjects. Plasma catecholamine content was consistent with urinary values and supports the concept of an elevation in sympathetic activity over time at altitude. Mean and diastolic blood pressure as well as heart rate adjustments to high altitude correlated significantly with urinary norepinephrine excretion rates. It was concluded that 1) urinary and plasma catecholamine responses to 12 days of high-altitude exposure in women are similar to those previously documented to occur for men; 2) whereas no differences in catecholamine levels were observed between F- and L-phase assignments, for a given urinary norepinephrine excretion rate, blood pressure and heart rates were lower for F vs. L subjects; and 3) several cardiovascular adaptations associated with high-altitude exposure correlated with 24-h urinary norepinephrine excretion rates and thus sympathetic nerve activity.
Authors:
R S Mazzeo; A Child; G E Butterfield; J T Mawson; S Zamudio; L G Moore
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Publication Detail:
Type:  Clinical Trial; Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  84     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  1998 Apr 
Date Detail:
Created Date:  1998-05-05     Completed Date:  1998-05-05     Revised Date:  2013-09-26    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol (1985)     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1151-7     Citation Subset:  IM    
Affiliation:
Department of Kinesiology, University of Colorado, Boulder, Colorado 80309, USA.
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MeSH Terms
Descriptor/Qualifier:
Adrenal Glands / physiology
Adult
Altitude*
Blood Pressure / physiology
Catecholamines / blood,  metabolism*,  urine
Female
Follicular Phase / physiology
Heart Rate / physiology
Hemodynamics / physiology
Humans
Luteal Phase / physiology
Menstrual Cycle / physiology
Progesterone / blood
Sympathetic Nervous System / physiology
Grant Support
ID/Acronym/Agency:
5-01 RR-00051/RR/NCRR NIH HHS; HL-14985/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
0/Catecholamines; 57-83-0/Progesterone

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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