title: [Estrogen attenuates the pressor response mediated by the group III mechanoreflex].
abstract: OBJECTIVE
  We investigated the effects of group III mechanoreceptors to cardiovascular responses in both pre-menopausal woman and post-menopausal woman during passive ankle dorsiflexion (PAD).
  
  
  METHODS
  Twenty healthy volunteers (10 post-menopausal women and 10 pre-menopausal women) were recruited for this study. Stroke volume (SV), heart rate (HR), cardiac output (CO), and total vascular conductances (TVC) were measured continuously throughout the experiment. To stimulate the group III mechanoreceptors, PAD was performed for one minute.
  
  
  RESULTS
  The results showed that mean arterial pressure (MAP) mediated by the mechanoreflex activation was significantly increased in both groups. However, this pressor response was significantly higher in post-menopausal women. This reflex significantly increased both SV and CO in pre-menopausal women, while there were no differences in post-menopausal women. There was no difference in HR in either group. The mechanoreflex significantly decreased TVC in post-menopausal woman, while there was no difference in pre-menopausal woman.
  
  
  CONCLUSIONS
  The results indicate that the excessive pressor response mediated by the mechanoreflex occurs due to overactivity of group III mechanorecptors and the mechanism is produced mainly via peripheral vasoconstriction in post-menopausal women.
authors.affiliation: Graduate School of Physical Education, Kyung Hee University, Yongin, Korea.
authors.forename: Seung-Ae
authors.initials: SA
authors.lastname: Park
authors.forename: Jong-Kyung
authors.initials: JK
authors.lastname: Kim
mesh_terms: D000368:Aged; D001794:Blood Pressure; D015992:Body Mass Index; D002302:Cardiac Output; D004967:Estrogens / Q000378:metabolism*; D005260:Female; D006339:Heart Rate; D006801:Humans; D008465:Mechanoreceptors; D008875:Middle Aged; D017698:Postmenopause; D017697:Premenopause; D012026:Reflex, Stretch / Q000502:physiology*; D013318:Stroke Volume
chemical_list: D004967:Estrogens