| Reflex haemodynamic responses caused by distension of the uterus in anaesthetized pigs. | |
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MedLine Citation:
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PMID: 9089533 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The present study was undertaken in anaesthetized pigs to determine whether distension of the uterus reflexly affects the aortic blood pressure, heart rate, left ventricular inotropic state and the coronary circulation. Experiments were performed in 17 pigs anaesthetized with alpha-chloralose and artificially ventilated. Coronary blood flow was measured with an electromagnetic flowmeter positioned around the origin of the left circumflex coronary artery. The uterus was distended by injecting 20 ml warm Ringer solution into a balloon positioned within the uterus (mean transmural pressure of about 17 mmHg). Distension of the uterus without controlling any haemodynamic variable caused an increase in aortic blood pressure. When this response was prevented, an increase in heart rate was obtained in each animal. When the heart rate and blood pressure responses were prevented, the distension did not cause significant changes in the maximum rate of change of left ventricular pressure, but always caused a decrease in mean coronary blood flow. In five pigs, the increase in heart rate and the decrease in mean coronary blood flow were graded by step increments of distension. In six pigs, the haemodynamic responses to distension of the uterus were not affected by the administration of atropine. In 12 pigs, which included the six given atropine, the increase in heart rate was abolished by the administration of propranolol and the increase in aortic blood pressure and the decrease in mean coronary blood flow were abolished by the subsequent administration of phentolamine. In the remaining five pigs, the haemodynamic responses caused by uterine distension were abolished by the administration of bretylium tosylate. The present study showed that distension of the uterus in anaesthetized pigs primarily caused reflex increases in heart rate and aortic blood pressure and coronary vasoconstriction. These reflex responses were mediated by efferent sympathetic mechanisms. |
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Authors:
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G Vacca; A Battaglia; E Grossini; D A Mary; C Molinari; N Surico |
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Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Journal of the autonomic nervous system Volume: 63 ISSN: 0165-1838 ISO Abbreviation: J. Auton. Nerv. Syst. Publication Date: 1997 Mar |
Date Detail:
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Created Date: 1997-09-29 Completed Date: 1997-09-29 Revised Date: 2007-11-15 |
Medline Journal Info:
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Nlm Unique ID: 8003419 Medline TA: J Auton Nerv Syst Country: NETHERLANDS |
Other Details:
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Languages: eng Pagination: 1-11 Citation Subset: IM; S |
Affiliation:
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Dipartimento di Scienze Mediche, Facoltà di Medicina e Chirurgia di Novara, Università di Torino, Italy. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Afferent Pathways
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drug effects,
physiology Anesthesia, General Animals Atropine / pharmacology Blood Pressure / drug effects Bretylium Tosylate / pharmacology Coronary Circulation / drug effects Efferent Pathways / drug effects, physiology Female Heart Rate / drug effects Hemodynamics* / drug effects Hypogastric Plexus / physiology* Mechanoreceptors / physiology* Myocardial Contraction / drug effects Parasympatholytics / pharmacology Phentolamine / pharmacology Pressure* Propranolol / pharmacology Reflex / drug effects, physiology* Swine Sympathetic Nervous System / drug effects, physiology* Sympatholytics / pharmacology Uterus / innervation* Ventricular Function, Left / drug effects |
| Chemical | |
Reg. No./Substance:
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0/Parasympatholytics; 0/Sympatholytics; 50-60-2/Phentolamine; 51-55-8/Atropine; 525-66-6/Propranolol; 61-75-6/Bretylium Tosylate |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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