Document Detail


Effects of oral contraceptives on sympathetic nerve activity during orthostatic stress in young, healthy women.
MedLine Citation:
PMID:  19828840     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Recent studies report that the menstrual cycle alters sympathetic neural responses to orthostatic stress in young, eumenorrheic women. The purpose of the present study was to determine whether oral contraceptives (OC) influence sympathetic neural activation during an orthostatic challenge. Based on evidence that sympathetic baroreflex sensitivity (BRS) is increased during the "low hormone" (LH) phase (i.e., placebo pills) in women taking OC, we hypothesized an augmented muscle sympathetic nerve activity (MSNA) response to orthostatic stress during the LH phase. MSNA, mean arterial pressure (MAP), and heart rate (HR) were recorded during progressive lower body negative pressure (LBNP; -5, -10, -15, -20, -30, -40 mmHg; 3 min/stage) in 12 healthy women taking OC (age 22 +/- 1 years). Sympathetic BRS was assessed by examining relations between spontaneous fluctuations of diastolic arterial pressure and MSNA. Subjects were examined twice: once during LH phase and once approximately 3 wk after LH during the "high hormone" phase (randomized order). Resting MSNA (10 +/- 2 vs. 13 +/- 2 bursts/min), MAP (85 +/- 3 vs. 84 +/- 3 mmHg), and HR (62 +/- 2 vs. 65 +/- 3 beats/min) were not different between phases. MSNA and HR increased during progressive LBNP (P < 0.001), and these increases were similar between phases. Progressive LBNP did not change MAP during either phase. Sympathetic BRS increased during progressive LBNP, but these responses were not different between LH and high hormone phases. In conclusion, our results demonstrate that OCs do not alter cardiovascular and sympathetic neural responses to an orthostatic challenge in young, healthy women.
Authors:
Jason R Carter; Jenna C Klein; Christopher E Schwartz
Publication Detail:
Type:  Clinical Trial; Comparative Study; Journal Article; Research Support, N.I.H., Extramural     Date:  2009-10-14
Journal Detail:
Title:  American journal of physiology. Regulatory, integrative and comparative physiology     Volume:  298     ISSN:  1522-1490     ISO Abbreviation:  Am. J. Physiol. Regul. Integr. Comp. Physiol.     Publication Date:  2010 Jan 
Date Detail:
Created Date:  2009-12-24     Completed Date:  2010-01-11     Revised Date:  2011-07-19    
Medline Journal Info:
Nlm Unique ID:  100901230     Medline TA:  Am J Physiol Regul Integr Comp Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  R9-R14     Citation Subset:  IM    
Affiliation:
Dept. of Exercise Science, Michigan Technological Univ., 1400 Townsend Drive, Houghton, MI 49931, USA. jcarter@mtu.edu
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MeSH Terms
Descriptor/Qualifier:
Androstenes / pharmacology
Baroreflex / physiology
Blood Pressure / physiology
Contraceptives, Oral / pharmacology*
Desogestrel / pharmacology
Estradiol / blood
Female
Heart Rate / physiology
Humans
Lower Body Negative Pressure / adverse effects
Menstrual Cycle / blood,  physiology
Muscle, Skeletal / innervation*,  physiology
Norethindrone / pharmacology
Orthostatic Intolerance / etiology,  physiopathology*
Progesterone / blood
Rest / physiology
Sympathetic Nervous System / drug effects*,  physiology
Young Adult
Grant Support
ID/Acronym/Agency:
HL-088689/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
0/Androstenes; 0/Contraceptives, Oral; 50-28-2/Estradiol; 54024-22-5/Desogestrel; 57-83-0/Progesterone; 67392-87-4/drospirenone; 68-22-4/Norethindrone
Comments/Corrections

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


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