Effects of the ovarian cycle on sympathetic neural outflow during static exercise
Deutscher übersetzter Titel: | Auswirkungen des Ovarialzyklus auf die Aktivierung des sympathischen Nervensystems waehrend statischer Muskelarbeit |
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Autor: | Ettinger, S.M.; Silber, D.H.; Gray, K.S.; Smith, M.B.; Yang, Q.X.; Kunselman, A.R.; Sinoway, L.I. |
Erschienen in: | Journal of applied physiology |
Veröffentlicht: | 85 (1998), 6, S. 2075-2081, Lit. |
Format: | Literatur (SPOLIT) |
Publikationstyp: | Zeitschriftenartikel |
Medienart: | Gedruckte Ressource |
Sprache: | Englisch |
ISSN: | 8750-7587, 0021-8987, 0161-7567, 1522-1601 |
Schlagworte: | |
Online Zugang: | |
Erfassungsnummer: | PU199901306658 |
Quelle: | BISp |
Abstract des Autors
We compared reflex responses to static handgrip at 30% maximal voluntary contraction (MVC) in 10 women (mean age 24.1+/-1.7 yr) during two phases of their ovarian cycle: the menstrual phase (days 1-4) and the follicular phase (days 10-12). Changes in muscle sympathetic nerve activity (MSNA; microneurography) in response to static exercise were greater during the menstrual compared with follicular phase (phase effect P=0.01). Levels of estrogen were less during the menstrual phase (75+/-5.5 vs. 116+/-9.6 pg/ml, days 1-4 vs. days 10-12; P=0.002). Generated tension did not explain differences in MSNA responses (MVC: 29.3+/-1.3 vs. 28.2+/-1.5 kg, days 1-4 vs. days 10-12; P=0.13). In a group of experiments with the use of 31P-NMR spectroscopy, no phase effect was observed for H+ and H2PO4- concentrations (n=5). During an ischemic rhythmic handgrip paradigm (20% MVC), a phase effect was not observed for MSNA or H+ or H2PO4- concentrations, suggesting that blood flow was necessary for the expression of the cycle-related effect. The present studies suggest that, during static handgrip exercise, MSNA is increased during the menstrual compared with the follicular phase of the ovarian cycle. Verf.-Referat