Linked Life Data

2494196

Source:http://linkedlifedata.com/resource/pubmed/id/2494196

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1989-4-25
pubmed:abstractText
12-0-tetradecanoyl-phorbol-13-acetate (TPA) can significantly reduce the Ca-ionophore-induced rise in the intracellular calcium concentration (Cai) of T lymphocytes measured by quin2 or fura-2 fluorescence. This counteraction of TPA is maximal at a preincubation of 90 min at TPA concentrations higher than 20 nM. 45Ca uptake and efflux measurements directly indicate that TPA does not activate the calcium extrusion systems in thymocytes but impairs the Ca-transporting ability of Ca-ionophores. TPA causes no immobilization of the Ca-ionophores as it is demonstrated by the lack of significant changes in fluorescence and fluorescence polarisation of A23187 during TPA incubation. Similarly the energy transfer between the Tyr, Try groups of membrane proteins and A23187 shows no significant difference in control and TPA treated thymocytes. This indicates that A23187 is not in a membrane protein-bound form after TPA preincubation. The intracellular heavy metal chelator, N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) restores the ionophoretic ability of Ca-ionophores in TPA pretreated cells to the control level. Diacyl-glycerols also impair the Ca-transporting ability of Ca-ionophores. TPEN prevents this effect as well. These findings suggest that TPA and diacyl-glycerols may cause an increase in the availability of intracellular heavy metal ions. Our results may reflect a new, physiologically important mechanism of the action of diacyl-glycerols and phorbol esters.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9541
pubmed:author
pubmed:issnType
Print
pubmed:volume
138
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
593-602
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Tumor promoter 12-0-tetradecanoyl-phorbol-13-acetate (TPA) can reduce the Ca-transporting ability of Ca-ionophores in T lymphocytes: the involvement of intracellular heavy metal ions.
pubmed:affiliation
Institute of Biochemistry I., Semmelweis University, School of Medicine, Budapest, Hungary.
pubmed:publicationType
Journal Article