Linked Life Data

2958621

Source:http://linkedlifedata.com/resource/pubmed/id/2958621

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1987-11-5
pubmed:abstractText
Dopamine receptors in the 7315a transplantable rat anterior pituitary tumor were characterized using radioligand binding assays with [3H]spiroperidol ([3H]SPD) and assays of adenylate cyclase activity. Scatchard analysis of the binding of [3H]SPD yielded linear plots and a Kd value of 73 pM. Studies of the inhibition of the binding of [3H]SPD were performed with a series of competing ligands, including the antagonists domperidone, (+)-butaclamol and sulpiride and the agonists dopamine, bromocriptine and N-propylnorapomorphine. Inhibition curves for the antagonists gave Hill coefficients of approximately 1, consistent with the presence of only a single class of binding sites with a high affinity for [3H]SPD. In contrast, the Hill coefficient for dopamine was significantly less than 1. When assays were carried out in the presence of 300 microM GTP, the inhibition curve for dopamine was shifted to the right and the Hill coefficient increased to approximately 1. An effect of GTP on the affinity of a receptor for agonists is consistent with the existence of at least two agonist affinity states. Inhibition of the binding of [3H]SPD by the partial agonist bromocriptine was not affected when assays were carried out in the presence of GTP. The uniform low affinity of the selective serotonin antagonist ketanserin for these sites indicated that the radioligand was not labeling serotonin-2 receptors in this tissue. A good correlation was observed between the Ki values for competing ligands measured in the tumor and in homogenates of rat striatal tissue. Dopamine was shown to inhibit forskolin-stimulated adenylate cyclase activity.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0022-3565
pubmed:author
pubmed:issnType
Print
pubmed:volume
242
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
950-6
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Characterization of D-2 dopamine receptors in a tumor of the rat anterior pituitary gland.
pubmed:affiliation
Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.