| Attenuation of exercise vasodilatation by adenosine deaminase in anaesthetized dogs. | |
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MedLine Citation:
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PMID: 1798047 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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1. In dogs anaesthetized with sodium pentobarbitone and artificially ventilated, the gracilis muscles were vascularly isolated and perfused at a constant flow of 28.4 +/- 4.6 ml min-1 (100 g muscle tissue)-1 (99.8 +/- 4.5% of maximum free flow, means +/- standard error of the mean (S.E.M.), n = 9). 2. Three to five minutes of electrical stimulation of the cut peripheral end of the obturator nerve (4 Hz, 6 V, 0.2 ms) resulted in muscle contraction (0.61 +/- 0.14 kg (100 g)-1 during solvent infusion and 0.56 +/- 0.10 kg (100 g)-1 during intra-arterial adenosine deaminase infusion (50 U min-1) and an immediate decrease in arterial perfusion pressure from 184.5 +/- 8.1 mmHg to 148.2 +/- 5.7 mmHg (18.7 +/- 3.4% decrease) during solvent infusion, and from 193.5 +/- 7.16 to 142.0 +/- 10.2 mmHg (25.4 +/- 6.1% decrease) during adenosine deaminase infusion 10 s after the commencement of muscle stimulation. After about 5 min of muscle contractions, the arterial perfusion pressure decreased to 120.8 +/- 7.8 mmHg (32.9 +/- 5.8% decrease) during solvent infusion, and to 152.8 +/- 11.2 mmHg (20.9 +/- 5.3% decrease) during adenosine deaminase infusion (i.e. 37.9 +/- 6.2% attenuation of the fall in arterial perfusion pressure). The time taken for 90% recovery of the arterial perfusion pressure was 72.1 +/- 10.9 s during solvent infusion, and 51.5 +/- 9.3 s during adenosine deaminase infusion (P less than 0.05). 3. Adenosine (2 x 10(-3) mol l-1) infusion in the resting muscle during solvent infusion (final concentration in arterial blood 1.3 x 10(-4) +/- 6.0 x 10(-5) mol l-1) resulted in a 34.8 +/- 7.2% fall in arterial perfusion pressure but a fall of only 7.2 +/- 1.8% during adenosine deaminase infusion (50 U min-1; P less than 0.05; n = 5) indicating that adenosine deaminase infused at 50 U min-1 was more than adequate to metabolize endogenous adenosine produced during muscle contractions. 4. These data suggest that adenosine contributes about 40% to the sustained-exercise vasodilatation under constant high-flow conditions and also in post-exercise vasodilatation, but does not contribute to the initiation of exercise vasodilatation. |
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Authors:
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I P Goonewardene; F Karim |
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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: The Journal of physiology Volume: 442 ISSN: 0022-3751 ISO Abbreviation: J. Physiol. (Lond.) Publication Date: 1991 Oct |
Date Detail:
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Created Date: 1992-04-10 Completed Date: 1992-04-10 Revised Date: 2009-11-18 |
Medline Journal Info:
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Nlm Unique ID: 0266262 Medline TA: J Physiol Country: ENGLAND |
Other Details:
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Languages: eng Pagination: 65-79 Citation Subset: IM; S |
Affiliation:
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Department of Physiology, University of Leeds. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adenosine Deaminase
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pharmacology* Animals Blood Flow Velocity Dogs Electric Stimulation Muscle Contraction / drug effects Muscles / blood supply* Physical Exertion* Vasodilation / drug effects* |
| Chemical | |
Reg. No./Substance:
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EC 3.5.4.4/Adenosine Deaminase |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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