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Park and Kim: Estrogen Attenuates the Pressor Response Mediated by the Group III Mechanoreflex
Original Article
Journal of Korean Academy of Nursing

Journal of Korean Academy of Nursing 2011; 41(2): 191-196.

Published online: 30 April 2011

DOI: https://doi.org/10.4040/jkan.2011.41.2.191

Estrogen Attenuates the Pressor Response Mediated by the Group III Mechanoreflex

Seung-Ae Park1, Jong-Kyung Kim2

1Doctoral Student, Graduate School of Physical Education, Kyung Hee University, Yongin, Korea.

2Assistant Professor, Graduate School of Physical Education, Kyung Hee University, Yongin, Korea.

Address reprint requests to: Kim, Jong-Kyung. Graduate School of Physical Education, Kyung Hee University, 1 Seocheon-dong, Giheung-gu, Yongin 446-701, Korea. Tel: +82-31-201-2778, Fax: +82-31-201-3743, kyung19692002@khu.ac.kr

Received 4 September 2010       Accepted 15 April 2011

© 2011 Korean Society of Nursing Science

Abstract

Purpose

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.

Conclusion

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.

Keywords: Estrogen, Post-menopausal woman, Exercise pressor reflex, Group III mechanoreceptors, Cardiac output

Figures and Tables

Figure 1
Experimental foot ankle dorsiflexion
jkan-41-191-g001
Figure 2
Cardiovascular responses mediated by the mechanorefelx during foot ankle dorsiflexion.
Values are mean±standard error. PMW=Premenopausal woman; PTW=Postmenopausal woman; Black Bar: baseline; Gray Bar: mechanoreflex activation. *Significantly different from baseline value, p<.05; #Significantly different from PMW, p<.05; MAP=mean arterial pressure; HR=heart rate; SV=stroke volume; CO cardiac output; TVC=total vascular conductances.
jkan-41-191-g002
Table 1
Physical Characteristics of Participants
jkan-41-191-i001

Values are mean±standard error.

*p<.05 vs. PMW.

PMW=premenopausal woman; PTW=postmenopausal woman; SBP=systolic blood pressure; DBP=diastolic blood pressure.

Notes

This study is a thesis of master of science.

Notes

This work was supported by a grant from Kyung Hee University in 2006 (KHU-20061278).

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