| Reflex coronary vasoconstriction caused by gallbladder distension in anesthetized pigs. | |
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MedLine Citation:
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PMID: 8901672 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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BACKGROUND: Gallbladder distension in anesthetized pigs reflexly increases heart rate and arterial pressure by means of afferent vagal pathways and efferent sympathetic mechanisms. The effect of such distension on the coronary circulation is unknown. The present study was undertaken to determine whether gallbladder distension primarily causes reflex changes in left circumflex blood flow. METHODS AND RESULTS: In 21 pigs anesthetized with sodium pentobarbitone (16) or alpha-chloralose (5), left circumflex blood flow was measured with an electromagnetic flowmeter. A balloon positioned within the gallbladder was distended with volumes of Ringer's solution equal to the volumes of bile previously withdrawn (mean vol: 62 mL; mean gallbladder pressure: 12 mm Hg). Heart rate and arterial pressure were kept constant by atrial pacing and by a pressurized reservoir connected to the left femoral artery. Gallbladder distension always caused a decrease in circumflex blood flow. In 6 of the 16 sodium pentobarbitone-anesthetized pigs, this decrease was graded by step increments of distension. In 5 of these 16 pigs, the decrease in circumflex blood flow was not affected by atropine. In 10 of these 16 pigs, including those given atropine, the response was not affected by propranolol but was abolished by subsequently giving phentolamine. Cervical vagotomy abolished the coronary vasoconstriction in the remaining 6 pigs. In the 5 alpha-chloralose-anesthetized pigs, the response was not significantly affected by cutting the splanchnic nerves but was abolished by subsequent cervical vagotomy. CONCLUSIONS: The present study showed that innocuous distension of the gallbladder in anesthetized pigs caused a reflex coronary vasoconstriction that involved efferent sympathetic mechanisms related to alpha-adrenoceptors and afferent vagal pathways. |
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Authors:
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G Vacca; A Battaglia; E Grossini; D A Mary; C Molinari |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Circulation Volume: 94 ISSN: 0009-7322 ISO Abbreviation: Circulation Publication Date: 1996 Nov |
Date Detail:
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Created Date: 1996-12-06 Completed Date: 1996-12-06 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 0147763 Medline TA: Circulation Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 2201-9 Citation Subset: AIM; IM |
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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Adjuvants, Anesthesia
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pharmacology Adrenergic alpha-Antagonists / pharmacology Adrenergic beta-Antagonists / pharmacology Afferent Pathways / physiology Anesthesia Animals Atropine / pharmacology Coronary Circulation / physiology* Coronary Vessels / innervation, physiology* Efferent Pathways / physiology Gallbladder / innervation, physiology* Isotonic Solutions Parasympatholytics / pharmacology Pentobarbital / pharmacology Phentolamine / pharmacology Propranolol / pharmacology Receptors, Adrenergic, alpha / physiology Reflex / physiology Regional Blood Flow / drug effects, physiology Splanchnic Nerves / surgery Swine Vagotomy Vagus Nerve / physiology, surgery Vasoconstriction / physiology* |
| Chemical | |
Reg. No./Substance:
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0/Adjuvants, Anesthesia; 0/Adrenergic alpha-Antagonists; 0/Adrenergic beta-Antagonists; 0/Isotonic Solutions; 0/Parasympatholytics; 0/Receptors, Adrenergic, alpha; 50-60-2/Phentolamine; 51-55-8/Atropine; 525-66-6/Propranolol; 76-74-4/Pentobarbital; 8022-63-7/Ringer's lactate |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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