Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1990-8-13
pubmed:abstractText
Studies of the coronary circulation have divided vascular resistances into three large components: large vessels, small resistance vessels, and veins. Studies of the epicardial microcirculation in the beating heart using stroboscopic illumination have suggested that resistance is more precisely controlled in different segments of the circulation. Measurements of coronary pressure in different sized arteries and arterioles have indicated that under normal conditions, 45-50% of total coronary vascular resistance resides in vessels larger than 100 microns. This distribution of vascular resistance can be altered in a nonuniform manner by a variety of physiological (autoregulation, increases in myocardial oxygen consumption, sympathetic stimulation) and pharmacological stimuli (norepinephrine, papaverine, dipyridamole, serotonin, vasopressin, nitroglycerin, adenosine, and endothelin). Studies of exchange of macromolecules in the microcirculation using fluorescent-labeled dextrans have also identified the size of the small pore (35-50 A) in coronary microvessels that can be altered by myocardial ischemia. Studies of the coronary microcirculation have demonstrated that the control of vascular resistance is extremely complex, and mechanisms responsible for these heterogeneous responses need further examination.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0009-7322
pubmed:author
pubmed:issnType
Print
pubmed:volume
82
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1-7
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Understanding the coronary circulation through studies at the microvascular level.
pubmed:affiliation
Department of Internal Medicine, University of Iowa, Iowa City 52242.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Review, Research Support, Non-U.S. Gov't