Linked Life Data

6748957

Source:http://linkedlifedata.com/resource/pubmed/id/6748957

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1984-9-18
pubmed:abstractText
The effect of vasomotor tone on blood flow estimates was evaluated in the hamster cheek pouch and cremaster muscle microcirculation. The products of arteriolar cross-sectional area and red blood cell velocity were calculated in three different cases: (1) at arteriolar bifurcations, (2) in short segments of an arteriole constricted by iontophoretic application of norepinephrine, and (3) at randomly selected second- and third-order arterioles. Vasodilation of the microcirculation was induced by topical application of adenosine. Vasoconstriction was induced by elevation of superfusion solution PO2. If true volume flow is accurately estimated by this method then: the sum of measured branch flows at a bifurcation should equal feed flow; measured flow through constricted arteriolar segments should equal flow proximal or distal to the constricted segment; and, following experimental manipulations, relative changes in estimated flow in second- and third-order arterioles should be equal. Our findings suggest that the blood flow estimates were not always accurate. The sum of branch flows was equal to feed flow only across bifurcations with low or resting vascular smooth muscle tone. During vasoconstriction, feed flow averaged 40% higher than the sum of downstream flows. In addition, estimated flow was 15% lower in constricted segments of an arteriole compared to dilated contiguous segments of the vessel. During alterations in vasomotor state, estimated fractional changes in flow in second- and third-order arterioles differed by more than sixfold. Therefore, blood flow estimates with the dual-slit method may not be reliable under conditions of high vasomotor tone. We speculate that the error may result largely from uncertainties in the diameter measurement.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0026-2862
pubmed:author
pubmed:issnType
Print
pubmed:volume
28
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
23-36
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
Inaccuracies in blood flow estimates in microvessels during arteriolar vasoconstriction.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.