| Baroreflex control of coronary blood flow varies regionally in awake dogs. | |
| | |
MedLine Citation:
|
PMID: 8911727 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
1. Baroreflex responses to changes in aortic pressure were measured simultaneously in three main coronary regions of awake dogs. 2. Pulsed Doppler flow probes were mounted at prior surgery on the right, circumflex and anterior descending coronary arteries; the animals were placed in complete heart block and the left ventricle was paced. After 2-4 weeks recovery, baroreflexes were evoked by inflating a balloon catheter placed in the mid-thoracic aorta via the femoral arteriotomy. Flow and pressure data were collected at rest, and during acute (8s) and steady-state (25s) baroreflex challenge. 3. Changing ventricular rate alone caused a fall in aortic pressure at low rates; however, over the range 60 to 180 b.p.m., circumflex and anterior descending coronary flow and conductance changed directly with ventricular rate, but right coronary flow and conductance remained unchanged. 4. Acute aortic pressure elevation increased flow at 8s in all beds at all rates. Conductance effects at 60 b.p.m. were negligible in all three beds, but rose at 100 and 180 b.p.m. in the right and circumflex beds. 5. Sustained aortic pressure elevation (25s) caused flow to return towards control in all beds ventricular rates, but in the right coronary at 60 b.p.m. flow fell below control. Conductance at this time was unchanged at all rates in the anterior descending bed, fell modestly in the circumflex, and decreased to below resting in the right coronary bed. 6. Baroreflex control of coronary flow and conductance thus varies between territories, and within territories, depending on ventricular rate. The right coronary bed appears to be regulated by a bidirectional, baroreflex-linked mechanism, which is functionally opposite in action to that found in most vascular beds. |
| | |
Authors:
|
A W Quail; D B Cottee; S W White; W L Porges; E J Hennessy |
Related Documents
:
|
961587 - Propranolol in experimental myocardial ischemia: dissociation of effects on contraction... 7979827 - Cardiovascular effects of krn2391 in anesthetized dogs: a comparison with cromakalim an... 7034937 - Clinical implications of the blood pressure response to exercise. 3652427 - The functional border zone in conscious dogs. 10461237 - Inter-laboratory comparisons: approaching a new standard for prosthetic heart valve tes... 16374687 - Quantitative analysis of paradoxical interventricular septal motion following correctiv... |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
|
Title: Clinical and experimental pharmacology & physiology Volume: 23 ISSN: 0305-1870 ISO Abbreviation: Clin. Exp. Pharmacol. Physiol. Publication Date: 1996 Oct-Nov |
Date Detail:
|
Created Date: 1997-02-19 Completed Date: 1997-02-19 Revised Date: 2008-11-21 |
Medline Journal Info:
|
Nlm Unique ID: 0425076 Medline TA: Clin Exp Pharmacol Physiol Country: AUSTRALIA |
Other Details:
|
Languages: eng Pagination: 866-73 Citation Subset: IM |
Affiliation:
|
Discipline of Human Physiology, Faculty of Medicine and Health Sciences, University of Newcastle, NSW, Australia. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Animals Aorta / physiology Baroreflex / physiology* Benzopyrans / pharmacology Blood Pressure / physiology Coronary Circulation / physiology* Dogs Ethanolamines / pharmacology Female Heart / physiology Heart Rate / physiology Hemodynamics / drug effects, physiology Male Pulmonary Artery / physiology Vasodilator Agents / pharmacology Ventricular Function Ventricular Function, Right / physiology Wakefulness |
| Chemical | |
Reg. No./Substance:
|
0/Benzopyrans; 0/Ethanolamines; 0/Vasodilator Agents; 99200-09-6/nebivolol |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Foetal metabolism, placental transfer and origin of gastrin releasing peptide in the sheep.
Next Document: Role of renal dopaminergic activity on renal sodium-water metabolism in congestive heart failure.