Linked Life Data

2900071

Source:http://linkedlifedata.com/resource/pubmed/id/2900071

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1988-9-21
pubmed:abstractText
1. We have examined the effects of guanine nucleotides on ACTH secretion from digitonin-permeabilized AtT-20 cells, with the aim of analyzing the involvement of GTP-binding proteins (G proteins) in the secretory process. 2. AtT-20 cells permeabilized with 20 microM digitonin displayed calcium-dependent secretion. The EC50 of calcium was approximately 2 microM and the maximal stimulation was 350% of basal release. 3. Nonhydrolyzable guanine nucleotides also stimulated ACTH release, in a virtually Ca2+-free medium. The EC50 of guanosine 5'-(3-O-thio)triphosphate (GTP gamma S) was approximately 15 microM and the maximal stimulation was approximately 230% of basal release. The effects of calcium and guanine nucleotides were not additive. 4. In the presence of the inhibitory hormone, somatostatin guanine nucleotides inhibited the calcium-stimulated secretion. 5. Both the stimulatory and the inhibitory effects on secretion of guanine nucleotides were independent of changes in cyclic AMP (cAMP) and calcium. It is suggested that G proteins influence an unknown step in the secretion process, which would be near or at the exocytotic site. 6. The results can be explained by assuming the existence of two types of G proteins, one with stimulatory effects on exocytotic release (GeS) and another with inhibitory effects (GeI).
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0272-4340
pubmed:author
pubmed:issnType
Print
pubmed:volume
8
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
129-38
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Dual regulation of ACTH secretion by guanine nucleotides in permeabilized AtT-20 cells.
pubmed:affiliation
Neuroendocrinology Unit, Istituto di Ricerche Farmacologiche Mario, Negri, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't