Linked Life Data

10385424

Source:http://linkedlifedata.com/resource/pubmed/id/10385424

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
1999-7-15
pubmed:abstractText
This study examined the effect of salmon calcitonin (sCT) on hypothalamic tyrosine hydroxylase (TH) activity and evaluated the cellular signaling mechanisms involved in the response. Fetal hypothalamic cells were cultured in a defined medium and treated with sCT and/or specific protein kinase inhibitors on day 14 in vitro. sCT (0.1-10 nM) increased both TH activity and cellular cAMP content in a concentration-dependent manner. sCT (10 nM) increased TH activity to 150-175% of control values and resulted in a 10-fold increase in cellular cAMP content. Both the C1a and C1b CT receptor isoforms were present in the cultures, as assessed by RT-PCR. Rp-adenosine 3',5'-cyclic monophosphothioate (Rp-cAMPS), a cAMP antagonist, and H-8, a cyclic nucleotide kinase inhibitor, blocked the sCT-induced increase in TH activity, with complete abolition of the response observed at concentrations of 1 mM and 5 microM, respectively. sCT (10 nM) increased radiolabeled phosphate incorporation into TH protein to 169% of control values and 1 mM Rp-cAMPS completely blocked this effect. In contrast, neither Calphostin C, a protein kinase C inhibitor, nor U-73122, a phospholipase C inhibitor, significantly altered the ability of sCT to increase TH activity. Likewise, the sCT-induced increase in TH activity was observed after pretreating the cells with either BAPTA/AM, an intracellular calcium chelator, or thapsigargin, an inhibitor of the endoplasmic reticulum calcium pump. These data indicate that sCT has a profound stimulatory effect on TH activity in fetal hypothalamic cells and that enhanced phosphorylation of TH coincides with the sCT-induced increase in enzyme activity. Moreover, CT receptors, which are linked to cAMP production, are expressed in the hypothalamic cells and a cAMP-dependent mechanism mediates the sCT-induced activation and phosphorylation of TH.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
140
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3273-81
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
3,5 cyclic adenosine monophosphate mediates the salmon calcitonin-induced increase in hypothalamic tyrosine hydroxylase activity.
pubmed:affiliation
Department of Physiology, Southern Illinois University School of Medicine, Carbondale 62901-6512, USA. larbogast@som.siu.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't