Linked Life Data

2675633

Source:http://linkedlifedata.com/resource/pubmed/id/2675633

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3 Pt 2
pubmed:dateCreated
1989-10-17
pubmed:abstractText
In isolated rabbit common carotid, internal carotid, and basilar arteries denuded of endothelium, mounted for measurement of contractile activity, and contracted with 10 microM serotonin (common and internal carotid) or 100 microM uridine 5'-triphosphate (UTP; basilar), 20 min of severe (PO2 = 15 Torr) and moderate (PO2 = 35 Torr) hypoxia relaxed initial tensions to 17, 6, and 16% and 18, 7, and 61% of control, respectively. The corresponding values in arteries contracted with 120 mM potassium-Krebs solution were 42, 60, and 73% and 57, 72, and 88%. These data indicate that the main determinants of the responses to hypoxia were intrinsic to the vessel walls of these arteries and that complete depolarization attenuated but did not eliminate the effects of these mechanisms. Superimposed on these intrinsic mechanisms were the effects of the endothelium, which were evaluated by several methods, including integration of the area between the 20-min response time courses of corresponding intact and denuded segments. Positive and negative integrated area values indicated endothelial vasoconstrictor [endothelium-derived contracting factor (EDCF)] and vasodilator [endothelium-derived relaxing factor (EDRF)] influences, respectively. In common carotid, internal carotid, and basilar segments contracted with serotonin and/or UTP, these areas averaged 770, 354, and 44 min% during severe and 491, 189, and -411 min% during moderate hypoxia. Corresponding values during potassium contraction were 217, -271, and -356 min% and 52, -177, and -54 min%. Together, these findings suggest that 1) intrinsic vascular mechanisms contribute significantly to hypoxic cerebral vasodilation in the rabbit, 2) EDCF is more prominent but also may be more sensitive to depolarization than EDRF, 3) hypoxia promotes the simultaneous release of both EDCF and EDRF, and 4) the ratio of EDCF to EDRF released during hypoxia decreases as one moves from the rabbit common carotid to the internal carotid to the basilar arteries.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
257
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H824-33
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Direct effects of graded hypoxia on intact and denuded rabbit cranial arteries.
pubmed:affiliation
Department of Physiology, Loma Linda University School of Medicine, California 92350.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't