Linked Life Data

1902061

Source:http://linkedlifedata.com/resource/pubmed/id/1902061

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4 Pt 1
pubmed:dateCreated
1991-5-17
pubmed:abstractText
The contributions of intracellular and extracellular calcium to thyrotropin-releasing hormone (TRH)- and angiotensin II (ANG II)-stimulated prolactin (PRL) release and the role of calcium in dopaminergic inhibition of these events were examined because of unresolved controversies in these areas. Dispersed normal female rat anterior pituitary cells were used to evaluate radiocalcium fluxes and the intracellular calcium concentration ([Ca]i). Both peptides increased PRL release, fractional 45Ca2+ efflux, and [Ca]i in a spike and plateau pattern, and neither increased 45Ca2+ uptake. In a low-calcium buffer, TRH and ANG II stimulated less than 5% of the normal PRL response, yet efflux was at least 50% of normal and [Ca]i was 20-40% of normal. Dopamine reduced TRH-stimulated PRL release by greater than 90% and abolished the plateau, yet the calcium responses to TRH were at least 50% of normal. Although dopamine prevented the plateau component of peptide-stimulated [Ca]i, the plateau phase of efflux persisted. Thus TRH and ANG II may control at least two cell-associated calcium pools, one readily depleted and the other highly resistant to depletion, without evidence for stimulation of calcium uptake. Dopamine inhibits PRL release stimulated by these peptides, with a relatively greater influence on the plateau component, through mechanisms only minimally related to calcium flux. Dopamine may slightly increase the extrusion of calcium mobilized by these peptides and thus may limit the anticipated increase in [Ca]i.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
260
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
E553-60
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Role of calcium in dopaminergic regulation of TRH- and angiotensin II-stimulated prolactin release.
pubmed:affiliation
Department of Neurology, University of Virginia Health Sciences Center, Charlottesville 22908.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.