α-Adrenergic control of blood flow during exercise: Effect of sex and menstrual phase

Jacqueline K. Limberg, Marlowe W. Eldridge, Lester T. Proctor, Joshua J. Sebranek, William G. Schrage

Research output: Contribution to journalArticlepeer-review

33 Scopus citations

Abstract

Sex differences exist in autonomic control of the cardiovascular system. This study was designed to directly test sex or female menstrual phase-related differences in α-adrenergic control of blood flow during exercise. We hypothesized that women would exhibit reduced α-adrenergic vasoconstriction compared with men during exercise; in addition, women would constrict less during the early luteal than the early follicular phase of the female menses. Young men (n=10) were studied once and women (n=9) studied twice, once during the early follicular phase and once during the early luteal phase of female menses. We measured forearm blood flow (FBF; Doppler ultrasound of the brachial artery) during rest and steady-state dynamic exercise (15 and 30% of maximal voluntary contraction, 20 contractions/min). A brachial artery catheter was inserted for the local administration of α-adrenergic agonists [phenylephrine (PE; α1) or clonidine (CL; α2)] . Blood flow responses to exercise [forearm vascular conductance (FVC)] were similar between all groups. At rest, infusion of PE or CL decreased FVC in all groups (40-60% reduction). Vasoconstriction to PE was abolished in all groups at 15 and 30% exercise intensity. Vasoconstriction to CL was reduced at 15% and abolished at 30% intensity in all groups; women had less CL-induced constriction during the early luteal than early follicular phase (P < 0.017, 15% intensity). These results indicate that vasodilator responses to forearm exercise are comparable between men and women and are achieved through similar paths of α-adrenergic vascular control at moderate intensities; this control may differ at low intensities specific to the female menstrual phase.

Original languageEnglish (US)
Pages (from-to)1360-1368
Number of pages9
JournalJournal of applied physiology
Volume109
Issue number5
DOIs
StatePublished - Nov 2010

Keywords

  • Exercise vasodilation
  • Functional sympatholysis

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

Fingerprint Dive into the research topics of 'α-Adrenergic control of blood flow during exercise: Effect of sex and menstrual phase'. Together they form a unique fingerprint.

Cite this