| Effects of time and vasoconstrictor tone on O2 extraction during hypoxic hypoxia. | |
| | |
MedLine Citation:
|
PMID: 681206 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
To test the role of peripheral vasoconstrictor tone in the efficient use of a limited O2 supply, three groups of anesthetized dogs were ventilated with 9.1% O2 until circulation failed. Two groups were alpha-blocked with phenoxybenzamine and one of those was volume expanded with dextran to restore blood pressure. After O2 utake was lowered in hypoxia, O2 uptake was linearly related to O2 delivery (cardiac output X arterial O2 content) with r = 0.94. The slope of that line was mathematically identical to the extraction ratio and it increased from 0.54 at 10 min to 0.87 at the end of hypoxia (r = 0.99). In both alpha-block groups O2 extraction remained constant with time, and O2 extraction in each alpha-block group was significantly less (P less than 0.01) than in the unblocked group. As further evidence of better O2 extraction, mixed venous partial O2 pressure was significantly less in the unblocked group, 6.2 +/- 3.4 Torr vs. 10.6 +/- 3.2 and 9.9 +/- 2.4 Torr with alpha block (P less than 0.01). Results after alpha-block indicated that a vigorous vasoconstrictor tone during hypoxia conserved O2 by promoting greater extraction by the tissues. |
| | |
Authors:
|
S M Cain |
Related Documents
:
|
23452496 - Comparison of three schemes of two-photon laser-induced fluorescence for co detection i... 2472846 - Hypoxia- and endothelium-mediated changes in the pharmacological responsiveness of circ... 7680496 - Potentiation by hypoxia of contractions caused by angiotensin ii in dog and monkey cere... 2768086 - Abr threshold is a function of blood oxygen level. 1832416 - Systolic blood pressure levels in black populations in sub-sahara africa, the west indi... 8871176 - Histopathological evaluation of retinal damage during intraocular hypertension in rabbi... |
Publication Detail:
|
Type: Journal Article |
Journal Detail:
|
Title: Journal of applied physiology: respiratory, environmental and exercise physiology Volume: 45 ISSN: 0161-7567 ISO Abbreviation: J Appl Physiol Publication Date: 1978 Aug |
Date Detail:
|
Created Date: 1978-10-18 Completed Date: 1978-10-18 Revised Date: 2003-11-14 |
Medline Journal Info:
|
Nlm Unique ID: 7801242 Medline TA: J Appl Physiol Country: UNITED STATES |
Other Details:
|
Languages: eng Pagination: 219-24 Citation Subset: IM; S |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Animals Anoxia Blood Pressure Dogs Muscle Tonus / drug effects Oxygen / blood* Oxygen Consumption* Phenoxybenzamine / pharmacology* Vasomotor System / drug effects, physiology* |
| Chemical | |
Reg. No./Substance:
|
59-96-1/Phenoxybenzamine; 7782-44-7/Oxygen |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Reflex effects of lung inflation and inhalation of halothane, ether, and ammonia.
Next Document: Relation between oxygen uptake and developed tension in dog skeletal muscle.