Linked Life Data

15220198

Source:http://linkedlifedata.com/resource/pubmed/id/15220198

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2004-6-28
pubmed:abstractText
Many metabolic factors affect the secretion of insulin from beta-cells and glucagon from alpha-cells of the islets of Langerhans to regulate blood glucose. Somatostatin from delta-cells, considered a local inhibitor of islet function, reduces insulin and glucagon secretion by activating somatostatin receptors in islet cells. Somatostatin secretion from delta-cells is increased by high glucose via glucose metabolism in a similar way to insulin secretion from beta-cells. However, it is unknown how low glucose triggers somatostatin secretion. Because L-glutamate is cosecreted with glucagon from alpha-cells under low-glucose conditions and acts as a primary intercellular messenger, we hypothesized that glutamate signaling triggers the secretion of somatostatin. In this study, we showed that delta-cells express GluR4c-flip, a newly identified splicing variant of GluR4, an (RS)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type ionotropic glutamate receptor of rat. After treatment with L-glutamate, AMPA, or kainate, secretion of somatostatin from isolated islets was significantly stimulated under low-glucose conditions. The glutamate-dependent somatostatin secretion was Ca(2+) dependent and blocked by 6-cyano-7-nitroquinoxaline-2,3-dione. Somatostatin in turn inhibited the secretion of L-glutamate and glucagon from alpha-cells. These results indicate that L-glutamate triggers somatostatin secretion from delta-cells by way of the GluR4c-flip receptor under low-glucose conditions. The released somatostatin may complete the feedback inhibition of alpha-cells. Thus, alpha- and delta-cells may communicate with each other through L-glutamate and somatostatin signaling.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0012-1797
pubmed:author
pubmed:issnType
Print
pubmed:volume
53
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1743-53
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
A novel variant of ionotropic glutamate receptor regulates somatostatin secretion from delta-cells of islets of Langerhans.
pubmed:affiliation
Department of Biochemistry, Faculty of Pharmaceutical Sciences, Okayama University, Okayama 700-8530, Japan. moriyama@pheasant.pharm.okayama-u.ac.jp
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't