Journal article
Acute resetting of carotid sinus baroreceptors. II. Possible involvement of electrogenic Na+ pump
The American journal of physiology, Vol.247(5 Pt 2), pp.H833-839
11/1984
DOI: 10.1152/ajpheart.1984.247.5.H833
PMID: 6093597
Abstract
In the accompanying manuscript [Am. J. Physiol. 247 (Heart Circ. Physiol. 16): H824-H832, 1984] we demonstrated that a mechanical mechanism alone cannot account for acute resetting of baroreceptors. To determine if changes in the activity of a baroreceptor electrogenic Na+ pump contributed to resetting, single-unit baroreceptor discharge was recorded from the carotid sinus nerve while resetting protocols were performed before and after exposing the vascularly isolated carotid sinus to treatments known to block the Na+ pump [ouabain and low extracellular K+ concentration ([K+]o)]. Ouabain (0.1-0.5 microgram/ml) blocked the increase in baroreceptor threshold pressure that occurred when intrasinus pressure was increased by 30 mmHg for 15 min [delta threshold = 16 +/- 3 (SE) mmHg before and 1.2 +/- 2.3 mmHg after ouabain]. In 12 experiments carotid sinus pressure was increased from 70 to 160 mmHg for 5 min and then returned to 70 mmHg for 10 min in the presence of both normal [K+]o (5.8 mM) and low [K+]o. Exposure to the low K+ solution resulted in a significantly smaller increase in threshold pressure when intrasinus pressure was increased from 70 to 160 mmHg (9 +/- 2.7 vs. 18 +/- 2.1 mmHg). When K+ was replaced, threshold pressure again increased by 18 +/- 2.3 mmHg, the increase in threshold was reversed. Thus, since ouabain blocked and low [K+]o attenuated acute resetting of the baroreceptors, we propose that changes in the activity of an electrogenic Na+ pump contribute to acute resetting.
Details
- Title: Subtitle
- Acute resetting of carotid sinus baroreceptors. II. Possible involvement of electrogenic Na+ pump
- Creators
- Cheryl M HeeschFrancois M AbboudMarc D Thames
- Resource Type
- Journal article
- Publication Details
- The American journal of physiology, Vol.247(5 Pt 2), pp.H833-839
- Publisher
- United States
- DOI
- 10.1152/ajpheart.1984.247.5.H833
- PMID
- 6093597
- ISSN
- 0002-9513
- eISSN
- 2163-5773
- Grant note
- HL-14388 / NHLBI NIH HHS HL-07121-07 / NHLBI NIH HHS HL-21158 / NHLBI NIH HHS
- Language
- English
- Date published
- 11/1984
- Academic Unit
- Molecular Physiology and Biophysics; Cardiovascular Medicine; Fraternal Order of Eagles Diabetes Research Center; Internal Medicine
- Record Identifier
- 9984025301902771
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