Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1994-8-18
pubmed:abstractText
In an attempt to elucidate the mechanism(s) underlying the paradoxical (inhibitory vs. stimulatory) effects of DA on PRL release, we treated permeabilized pituitary cells with antibodies directed against the carboxyl-terminus of the alpha-subunit of the guanine nucleotide binding protein, Gi3. Immunoneutralization of Gi alpha 3 completely blocked the inhibitory effect of 1000 nM DA on PRL release, as assessed by reverse hemolytic plaque assays. In contrast, DA at a 100-fold lower concentration (10 nM) had no effect on PRL release under control conditions, but elicited a stimulatory response in the presence of anti-Gi alpha 3. Examination of the frequency distribution of plaque sizes indicated that suppression and augmentation of PRL secretion by DA was not attributable to distinct subpopulations of lactotropes. Taken together, these data suggest that all pituitary lactotropes have the potential to respond to the inhibitory and stimulatory activities of DA. However, the stimulatory action of this monoamine is normally masked by tonic activation of Gi alpha 3 which couples DA to its inhibitory pathway.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
135
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
790-3
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Paradoxical effects of dopamine (DA): Gi alpha 3 mediates DA inhibition of PRL release while masking its PRL-releasing activity.
pubmed:affiliation
Dept. of Cell Biology and Anatomy, Medical University of South Carolina, Charleston 29425-2204.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.