Linked Life Data

2450195

Source:http://linkedlifedata.com/resource/pubmed/id/2450195

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1988-4-12
pubmed:abstractText
The influence of the endothelium on smooth muscle tone and the response of the pig right coronary artery to norepinephrine (NE) was studied. Isolated rings of artery with and without endothelium were stretched in the presence of nitroprusside to a tension previously determined to be optimal for contraction. During wash out of the nitroprusside, rings without endothelium spontaneously generated tone representing 24% of the contraction caused by potassium (120 mM); in rings with endothelium no significant spontaneous tone was observed. Relaxations were caused by NE in rings with endothelium contracted with prostaglandin F2 alpha (PGF2 alpha). In rings without endothelium, NE relaxed spontaneously generated tone as well as that produced by PGF2 alpha. Independent of the mode or degree of contraction, rings with endothelium were more sensitive to NE than rings without endothelium. The difference in sensitivity to NE between rings with and without endothelium was likely due to endothelial cell alpha-2 adrenoceptors, inasmuch as the difference was abolished by rauwolscine. In the presence of propranolol and prazosin, endothelium-dependent relaxations were observed which were also inhibited by rauwolscine. Nevertheless, beta adrenoceptors are the predominant mediator of the relaxation to NE of pig coronary smooth muscle, because propranolol caused a greater shift to the right of the relaxation induced by NE compared to that caused by endothelium removal. Accordingly, under resting conditions, NE caused contractions only in the presence of propranolol. These contractions were attenuated by prazosin or rauwolscine, but blocked only by a combination of both alpha adrenoceptor antagonists.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0022-3565
pubmed:author
pubmed:issnType
Print
pubmed:volume
244
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
550-5
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Influence of the endothelium on tone and the response of isolated pig coronary artery to norepinephrine.
pubmed:affiliation
Robert Dawson Evans Memorial Department of Clinical Research, Boston University Medical Center, Massachusetts.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't