NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Baroreflex modulation of sympathetic nerve activity to muscle in heat-stressed humansTo identify whether whole body heating alters arterial baroreflex control of muscle sympathetic nerve activity (MSNA), MSNA and beat-by-beat arterial blood pressure were recorded in seven healthy subjects during acute hypotensive and hypertensive stimuli in both normothermic and heat stress conditions. Whole body heating significantly increased sublingual temperature (P < 0.01), MSNA (P < 0.01), heart rate (P < 0.01), and skin blood flow (P < 0.001), whereas mean arterial blood pressure did not change significantly (P > 0.05). During both normothermic and heat stress conditions, MSNA increased and then decreased significantly when blood pressure was lowered and then raised via intravenous bolus infusions of sodium nitroprusside and phenylephrine HCl, respectively. The slope of the relationship between MSNA and diastolic blood pressure during heat stress (-128.3 +/- 13.9 U x beats(-1) x mmHg(-1)) was similar (P = 0.31) with normothermia (-140.6 +/- 21.1 U x beats(-1) x mmHg(-1)). Moreover, no significant change in the slope of the relationship between heart rate and systolic blood pressure was observed. These data suggest that arterial baroreflex modulation of MSNA and heart rate are not altered by whole body heating, with the exception of an upward shift of these baroreflex curves to accommodate changes in these variables that occur with whole body heating.
Document ID
20040088607
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Cui, Jian
(Institute for Exercise and Environmental Medicine, Presbyterian Hospital of Dallas Dallas 75231, Texas, United States)
Wilson, Thad E.
Crandall, Craig G.
Date Acquired
August 21, 2013
Publication Date
January 1, 2002
Publication Information
Publication: American journal of physiology. Regulatory, integrative and comparative physiology
Volume: 282
Issue: 1
ISSN: 0363-6119
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: HL-61388
CONTRACT_GRANT: HL-10488
Distribution Limits
Public
Copyright
Other
Keywords
NASA Discipline Cardiopulmonary
Non-NASA Center

Available Downloads

There are no available downloads for this record.
No Preview Available