Sympathetic Cardiac Influence and Arterial Blood Pressure Instability
dc.contributor.advisor | Shi, Xiangrong | |
dc.contributor.committeeMember | Downey, H. Fred | |
dc.contributor.committeeMember | Gwirtz, Patricia A. | |
dc.creator | Formes, Kevin John | |
dc.date.accessioned | 2019-08-22T19:33:49Z | |
dc.date.available | 2019-08-22T19:33:49Z | |
dc.date.issued | 2002-09-01 | |
dc.date.submitted | 2014-01-25T06:13:34-08:00 | |
dc.description.abstract | Formes, Kevin John, Sympathetic Cardiac Influence and Arterial Blood Pressure Instability. Master of Science (Biomedical Sciences) September 2002, 51 pp., 3 tables, 5 illustrations, 36 references. This study was designed to determine the role of β1-adrenoreceptors in arterial blood pressure (ABP) regulation during an orthostatic challenge. Metoprolol was used to block β1-adrenoreceptors. Atropine, a peripheral and central acting muscarinic blocker, was used to inhibit vagal influences on heart rate. Lower body negative pressure (LBNP) was used to stimulate an orthostatic hypotensive stimulus before and after receptor blockade. Metoprolol administration significantly increased baroreflex sensitivity (BRS) and significantly decreased the reflex increase baroreflex sensitivity (BRS) and significantly decreased the reflex increase in plasma renin activity (PRA) in response to a hypotensive stimulus. Therefore we suggest that the attenuation of PRA is counterbalanced by an increased heart rate reserve, which allows the heart rate to increase more in response to decreases in venous return. This increase in cardiac responsiveness was abolished with the administration of atropine. Therefore, we conclude that acute administration of metoprolol causes (i) improved ABP stability, as indicated by a diminished augmentation of low frequency (LF) ABP variability and (ii) attenuates the increase in PRA during LBNP induced central hypovolemic challenge. | |
dc.format.mimetype | application/pdf | |
dc.identifier.uri | https://hdl.handle.net/20.500.12503/26236 | |
dc.language.iso | en | |
dc.provenance.legacyDownloads | 0 | |
dc.subject | Cardiology | |
dc.subject | Cardiovascular System | |
dc.subject | Circulatory and Respiratory Physiology | |
dc.subject | Life Sciences | |
dc.subject | Medical Physiology | |
dc.subject | Medical Sciences | |
dc.subject | Medicine and Health Sciences | |
dc.subject | Systems and Integrative Physiology | |
dc.subject | Sympathetic cardiac influence | |
dc.subject | arterial blood pressure | |
dc.subject | instability | |
dc.subject | β1-adrenoreceptors | |
dc.subject | atropine | |
dc.subject | metoprolol | |
dc.subject | ABP | |
dc.subject | orthostatic challenge | |
dc.subject | plasma renin activity | |
dc.subject | lower body negative pressure | |
dc.subject | PRA | |
dc.subject | LBNP | |
dc.subject | central hypovolemic challenge | |
dc.subject | baroreflex sensitivity | |
dc.subject | heart rate | |
dc.title | Sympathetic Cardiac Influence and Arterial Blood Pressure Instability | |
dc.type | Thesis | |
dc.type.material | text | |
thesis.degree.department | Graduate School of Biomedical Sciences | |
thesis.degree.discipline | Biomedical Sciences | |
thesis.degree.grantor | University of North Texas Health Science Center at Fort Worth | |
thesis.degree.name | Master of Science |
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