Document Detail

Sex differences in the modulation of vasomotor sympathetic outflow during static handgrip exercise in healthy young humans.
MedLine Citation:
PMID:  21508291     Owner:  NLM     Status:  MEDLINE    
Sex differences in sympathetic neural control during static exercise in humans are few and the findings are inconsistent. We hypothesized women would have an attenuated vasomotor sympathetic response to static exercise, which would be further reduced during the high sex hormone [midluteal (ML)] vs. the low hormone phase [early follicular (EF)]. We measured heart rate (HR), blood pressure (BP), and muscle sympathetic nerve activity (MSNA) in 11 women and 10 men during a cold pressor test (CPT) and static handgrip to fatigue with 2 min of postexercise circulatory arrest (PECA). HR increased during handgrip, reached its peak at fatigue, and was comparable between sexes. BP increased during handgrip and PECA where men had larger increases from baseline. Mean ± SD MSNA burst frequency (BF) during handgrip and PECA was lower in women (EF, P < 0.05), as was ΔMSNA-BF smaller (main effect, both P < 0.01). ΔTotal activity was higher in men at fatigue (EF: 632 ± 418 vs. ML: 598 ± 342 vs. men: 1,025 ± 416 a.u./min, P < 0.001 for EF and ML vs. men) and during PECA (EF: 354 ± 321 vs. ML: 341 ± 199 vs. men: 599 ± 327 a.u./min, P < 0.05 for EF and ML vs. men). During CPT, HR and MSNA responses were similar between sexes and hormone phases, confirming that central integration and the sympathetic efferent pathway was comparable between the sexes and across hormone phases. Women demonstrated a blunted metaboreflex, unaffected by sex hormones, which may be due to differences in muscle mass or fiber type and, therefore, metabolic stimulation of group IV afferents.
Sara S Jarvis; Tiffany B VanGundy; M Melyn Galbreath; Shigeki Shibata; Kazunobu Okazaki; Miriam F Reelick; Benjamin D Levine; Qi Fu
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, N.I.H., Extramural     Date:  2011-04-20
Journal Detail:
Title:  American journal of physiology. Regulatory, integrative and comparative physiology     Volume:  301     ISSN:  1522-1490     ISO Abbreviation:  Am. J. Physiol. Regul. Integr. Comp. Physiol.     Publication Date:  2011 Jul 
Date Detail:
Created Date:  2011-07-04     Completed Date:  2011-09-08     Revised Date:  2013-06-30    
Medline Journal Info:
Nlm Unique ID:  100901230     Medline TA:  Am J Physiol Regul Integr Comp Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  R193-200     Citation Subset:  IM    
Institute for Exercise and Environmental Medicine, 7232 Greenville Ave., Suite 435, Dallas, TX 75231, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Blood Pressure / physiology
Cardiovascular Physiological Phenomena
Estrogens / physiology
Exercise / physiology*
Fatigue / physiopathology
Hand Strength / physiology*
Heart Rate / physiology
Menstrual Cycle / physiology
Progesterone / physiology
Sympathetic Nervous System / physiology*
Vasomotor System / physiology*
Grant Support
Reg. No./Substance:
0/Estrogens; 57-83-0/Progesterone

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

Previous Document:  Regulation of the expression of the avian uncoupling protein 3 by isoproterenol and fatty acids in c...
Next Document:  Thermal adaptation of the crucian carp (Carassius carassius) cardiac delayed rectifier current, IKs,...