Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1990-4-6
pubmed:abstractText
The purpose of this study was to investigate if myogenic responses of isolated coronary arterioles were dependent on an intact, functional endothelium. Arterioles were located in situ by intracoronary perfusion with india ink-gelatin solution and then dissected and cannulated at both ends with glass micropipettes. Intraluminal pressure was initially set at 60 cm H2O; then the pressure was altered in steps of 20 cm H2O over a range of 20-140 cm H2O. Arterioles developed spontaneous tone and exhibited a significant myogenic response in physiological saline solution (36 degrees -37 degrees C). Arteriolar dilation and constriction were observed at lower (20-60 cm H2O) and higher (60-140 cm H2O) pressures, respectively. The presence of a functional and automatically intact endothelium was confirmed by relaxation to the endothelium-dependent vasodilator bradykinin and by transmission electron microscopy, respectively. After mechanical denudation of the endothelium with a specially designed abrasive micropipette, spontaneous tone and myogenic responses were preserved. Denudation of the endothelium was verified functionally (no response to bradykinin) and with transmission electron microscopy. Moreover, the mechanical denudation technique did not deleteriously affect smooth muscle because vasoconstrictor and vasodilator responses to nonendothelial-dependent drugs were the same before and after denudation. In summary, the present study demonstrates that pressure-dependent responses occur in isolated coronary arterioles and that this response is not dependent on the endothelium. Therefore, pressure-induced changes in coronary arteriolar tone are a true myogenic response in that they originate from smooth muscle.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0009-7330
pubmed:author
pubmed:issnType
Print
pubmed:volume
66
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
860-6
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Coronary arteriolar myogenic response is independent of endothelium.
pubmed:affiliation
Department of Medical Physiology, College of Medicine, Texas A & M University, College Station 77843.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't