Linked Life Data

7688203

Source:http://linkedlifedata.com/resource/pubmed/id/7688203

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1993-9-2
pubmed:abstractText
It is now recognized that extracellular ATP can open a receptor-operated ion channel in a variety of cell types. In human lymphocytes this P2Z purinergic channel conducts Na+, K+, Rb+, Li+, and Ca2+ but its permeability to larger cations is not known. Fluorometric measurements were used to show that ATP4- induced the entry of Sr2+ (87 Da) and Ba2+ (137 Da) into human lymphocytes loaded with fura-2. Flow cytometry was used to show that ATP4- induced the entry of ethidium+ (314 Da) but that the larger propidium2+ cation (414 Da) was excluded. ATP(4-)-induced entry of both Ba2+ and ethidium+ showed features previously demonstrated for smaller cation permeants: (i) inhibition by amiloride analogs, (ii) sigmoid dependence of flux on ATP concentrations, and (iii) inhibition by extracellular Na+ ions. Specific inhibitors of L-type voltage-gated Ca2+ channels (nisoldipine and diltiazem) had no effect on ATP(4-)-induced Ba2+ influx. Suramin and reactive blue 2, which are recognized antagonists of ATP-operated purinergic receptors in other tissues, inhibited ATP-induced uptake of ethidium+ in lymphocytes with K1/2 of 61 and 69 microM, respectively. However, hexamethylene amiloride was a more potent inhibitor of ATP-induced ethidium+ uptake with a K1/2 of 13 microM. These data show that the ATP4- receptor-operated channel of human lymphocytes allows influx of cations as large as Ba2+ or ethidium+ and that this influx is inhibited by suramin and reactive blue 2.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0003-9861
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
305
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
54-60
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
The ATP4- receptor-operated channel (P2Z class) of human lymphocytes allows Ba2+ and ethidium+ uptake: inhibition of fluxes by suramin.
pubmed:affiliation
Haematology Department, Austin Hospital, Heidelberg, Victoria, Australia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't