Linked Life Data

1327244

Source:http://linkedlifedata.com/resource/pubmed/id/1327244

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1992-11-16
pubmed:abstractText
The interaction of alpha 1- and alpha 2-adrenoceptor constriction of isolated rat cremaster small arteries (mean diameter +/- SEM, 114 +/- 5 microns) with the myogenic mechanism was examined with in vitro videomicroscopy. Microdissected vessels were double-cannulated with glass micropipets in a tissue bath, and intraluminal pressure was set at 65 mm Hg baseline pressure. Norepinephrine (NE) concentration-response curves were obtained alone and in the presence of prazosin or rauwolscine to establish the concentration of NE required to selectively stimulate alpha 1- or alpha 2-adrenoceptors. A bimodal response was produced by NE alone, indicating interaction with more than one receptor population. Rauwolscine and prazosin each produced dextral displacement at low (< 0.1 microM) NE concentrations. However, while prazosin exhibited competitive antagonism, rauwolscine did not antagonize NE at concentrations > or = EC50 value. Thus, both alpha 1- and alpha 2-adrenoceptors mediate constriction at low NE concentrations, but only alpha 1-receptors contributed to constriction at intermediate and high concentrations. These data are in contrast to previous findings for the same vessels studied in vivo. Diameter responses to increases and decreases in transmural pressure from baseline were examined in the relaxed (passive) state with nitroprusside present, during spontaneous intrinsic tone, and during induced alpha 1- or alpha 2-tone (EC20 concentration of NE plus rauwolscine or prazosin). Myogenic constriction during increases in lumen pressure and myogenic inhibition of tone during decreases in pressure were greatest during alpha 2-tone, less during intrinsic tone and least during alpha 1-tone.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1018-1172
pubmed:author
pubmed:issnType
Print
pubmed:volume
29
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
313-21
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:articleTitle
In vitro analysis of alpha-adrenoceptor interactions with the myogenic response in resistance vessels.
pubmed:affiliation
Department of Physiology, University of North Carolina, Chapel Hill 27599-7545.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S.