| Isoflurane and the pulmonary vascular pressure-flow relation at baseline and during sympathetic alpha- and beta-adrenoreceptor activation in chronically instrumented dogs. | |
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MedLine Citation:
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PMID: 7879940 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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BACKGROUND: The extent to which isoflurane anesthesia alters systemic vascular regulation has received considerable attention. In contrast, the pulmonary vascular effects of isoflurane have not been elucidated. Our initial objective was to investigate the net effect of isoflurane on the baseline left pulmonary vascular pressure-flow (LPQ) relation compared with values measured in the conscious state. In addition, we assessed the extent to which isoflurane alters the pulmonary vascular responses to sympathetic alpha- and beta-adrenoreceptor activation. METHODS: Twelve conditioned mongrel dogs were chronically instrumented to measure the LPQ relation. LPQ plots were generated by continuously measuring the pulmonary vascular pressure gradient (pulmonary arterial pressure--left atrial pressure) and left pulmonary blood flow during gradual (approximately 1 min) inflation of a hydraulic occluder implanted around the right main pulmonary artery. LPQ plots were generated at baseline in the conscious and isoflurane-anesthetized states (n = 12). The pulmonary vascular dose-response relation to the sympathetic alpha-adrenoreceptor agonist phenylephrine also was investigated in conscious and isoflurane-anesthetized dogs (n = 6). Finally, after preconstriction with the thromboxane analogue U46619, the dose-response relation to the sympathetic beta-adrenoreceptor agonist isoproterenol was assessed in the conscious and isoflurane-anesthetized states (n = 8). RESULTS: Compared with values measured in the conscious state, isoflurane anesthesia had no net effect on the baseline LPQ relation. The magnitude of the pulmonary vasoconstrictor response to phenylephrine observed in conscious dogs was not altered during isoflurane anesthesia. In contrast, the pulmonary vasodilator response to isoproterenol was markedly potentiated (P < 0.01) during isoflurane anesthesia compared with that in the conscious state. CONCLUSIONS: These results indicate that isoflurane does not exert a net vasodilator influence on the pulmonary circulation at baseline. In contrast to the systemic circulation, the pulmonary vasoconstrictor response to sympathetic alpha-adrenoreceptor activation is maintained during isoflurane anesthesia. Surprisingly, the pulmonary vasodilator response to sympathetic beta-adrenoreceptor activation is actually potentiated during isoflurane. Thus, isoflurane anesthesia has differential effects on the canine pulmonary vascular responses to sympathetic alpha- and beta-adrenoreceptor activation. |
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Authors:
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P F Lennon; P A Murray |
Publication Detail:
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Type: Journal Article; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
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Title: Anesthesiology Volume: 82 ISSN: 0003-3022 ISO Abbreviation: Anesthesiology Publication Date: 1995 Mar |
Date Detail:
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Created Date: 1995-04-05 Completed Date: 1995-04-05 Revised Date: 2007-11-15 |
Medline Journal Info:
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Nlm Unique ID: 1300217 Medline TA: Anesthesiology Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 723-33 Citation Subset: AIM; IM |
Affiliation:
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Department of Anesthesiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Anesthesia, General Animals Blood Pressure Dogs Hemodynamics Isoflurane / pharmacology* Male Phenylephrine / pharmacology Propranolol / pharmacology Pulmonary Circulation / drug effects* Receptors, Adrenergic, alpha / physiology Receptors, Adrenergic, beta / physiology Regional Blood Flow / drug effects Vasodilation / drug effects Wakefulness |
| Grant Support | |
ID/Acronym/Agency:
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HL-38291/HL/NHLBI NIH HHS; HL-40361/HL/NHLBI NIH HHS |
| Chemical | |
Reg. No./Substance:
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0/Receptors, Adrenergic, alpha; 0/Receptors, Adrenergic, beta; 26675-46-7/Isoflurane; 525-66-6/Propranolol; 59-42-7/Phenylephrine |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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