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Muscle vasodilatation caused by hypoxia propagates upstream within the arteriolar wall
Author(s) -
Riemann Mads Achen,
HolsteinRathlou NielsHenrik,
TorpPedersen Christian
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a494-a
Subject(s) - arteriole , hyperoxia , vasodilation , capillary action , oxygen tension , anatomy , chemistry , microcirculation , hypoxia (environmental) , blood flow , vasoconstriction , oxygen , biophysics , materials science , medicine , biology , composite material , organic chemistry
Changes in oxygen tension regulate the diameter of arterioles supplying tissues with blood, but how changes in oxygen tension are transmitted from tissue to arteriole is still uncertain. We developed a method by which the oxygen tension in a capillary bed could be increased or decreased locally while maintaining normal oxygen tension in the arteriole supplying that region. The mouse cremaster muscle was used. An arteriole supplying a capillary bed was visualized over several millimetres. The capillary bed supplied by the arteriole was then selectively superfused with red blood corpuscle suspension or buffer equilibrated with either 95% nitrogen or 95% oxygen. Local hypoxia resulted in dilation of the arteriole and local hyperoxia resulted in constriction close to the capillary bed. One millimetre upstream we identified a propagated response of similar size as the local response. The observed dilation of approximately 13% corresponds to a 62% increase of blood flow. Buffer instead of red blood corpuscle suspension resulted in smaller changes in the same directions. If the arteriolar wall was subjected to local damage with light‐dye treatment between the two points of inspection the same changes as above were seen close to the capillary bed while changes upstream to the damaged vessel wall were abolished. This study demonstrates that hypoxia and hyperoxia in the capillary bed causes vasodilation and vasoconstriction which propagate upstream in the arteriole by a signal carried within the vessel wall.