| Alpha2 adrenergic receptors and the central control of breathing in the cane toad, Bufo marinus. | |
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MedLine Citation:
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PMID: 11282388 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The effect of adrenergic agents on the central control of breathing in the cane toad, Bufo marinus, was tested by applying adrenergic agents to the ventral medullary surface of decerebrate adult toads. Toads were unidirectionally ventilated while recording lung, buccal, and artery blood pressures (BPI), as well as heart rate (HR). Following a control period, filter paper pledgets soaked in the appropriate solution (epinephrine - 0.023, 0.05, 0.10, and 0.23 mM; norepinephrine - 0.002, 0.016, 0.032, and 0.16 mM; clonidine - 0.00375, 0.0375, and 0.375 mM; or yohimbine - 0.43) mM) were placed bilaterally on the ventral medullary surface. Epinephrine significantly increased the number of breaths (26%), lung amplitude (9%), and episode duration (21%), but had no effect on BP or HR. The alpha2-agonist. clonidine, significantly increased respiratory activity at moderate doses (0.0375 mM) and decreased activity at high doses (0.375 mM), however, it failed to elicit significant changes in BP or HR. Pretreatment with the alpha2-adrenoceptor antagonist, yohimbine (0.43 mM), blocked the clonidine induced changes in respiratory activity. Yohimbine had no effect on cardiorespiratory parameters. Norepinephrine had no effect on either cardiovascular or respiratory variables. Thus, it appears that an alpha2 adrenergic mechanism is involved in the central control of respiration in this lower vertebrate. |
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Authors:
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J E Rives; D G Bernard |
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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: Respiration physiology Volume: 125 ISSN: 0034-5687 ISO Abbreviation: Respir Physiol Publication Date: 2001 Apr |
Date Detail:
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Created Date: 2001-04-03 Completed Date: 2001-06-28 Revised Date: 2009-11-11 |
Medline Journal Info:
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Nlm Unique ID: 0047142 Medline TA: Respir Physiol Country: Netherlands |
Other Details:
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Languages: eng Pagination: 213-23 Citation Subset: IM |
Affiliation:
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Department of Biology, University of Texas at Arlington, 501 Nedderman Drive, Box 19498, Arlington, TX 76019, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adrenergic alpha-Agonists
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pharmacology Adrenergic alpha-Antagonists / pharmacology Animals Blood Pressure / drug effects, physiology Bufo marinus / physiology* Clonidine / pharmacology Decerebrate State / physiopathology Epinephrine / pharmacology Medulla Oblongata / drug effects, physiology Norepinephrine / pharmacology Receptors, Adrenergic, alpha-2 / physiology* Respiratory Mechanics / drug effects, physiology* Yohimbine / pharmacology |
| Chemical | |
Reg. No./Substance:
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0/Adrenergic alpha-Agonists; 0/Adrenergic alpha-Antagonists; 0/Receptors, Adrenergic, alpha-2; 146-48-5/Yohimbine; 4205-90-7/Clonidine; 51-41-2/Norepinephrine; 51-43-4/Epinephrine |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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