Linked Life Data

3755432

Source:http://linkedlifedata.com/resource/pubmed/id/3755432

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
21
pubmed:dateCreated
1986-9-17
pubmed:abstractText
The activation of human neutrophils by chemotactic peptides evokes a rapid change in membrane potential and an increase in cytoplasmic Ca2+ levels. These events are followed up to a minute later by detectable levels of microbicidal agents formed by the oxidative burst. Except for the latter, the sequence of events has remained unclear. We report here that a new fluorescent Ca2+ indicator developed by R. Tsien, Indo-1, has allowed us to resolve the temporal relationship between the rapid and transient cytoplasmic Ca2+ rise and the membrane potential change and to do so on very small samples by using a fluorescence-activated cell sorter. We have adapted a FACS 440 for simultaneous single cell membrane depolarization and cytoplasmic [Ca2+] detection in human neutrophils upon stimulation with formyl-methionyl-leucyl-phenylalanine (fMLP). A membrane potential probe, dipentyloxacarbocyanine, allows us to determine that the membrane potential change is fMLP dose-dependent and apparently biphasic. The depolarization is maximal 40 s after stimulation. In contrast, cytosolic [Ca2+], while fMLP-dose dependent, is maximal at 10 s and already decreasing rapidly when the cell has reached its lowest potential. It can be measured with Indo-1 which has a fluorescence emission (lambda ex = 357 nm) maximum at 485 nm when Ca2+-free and 405 nm when Ca2+-liganded. The ratio of these fluorescences may then be calibrated in terms of cytoplasmic Ca2+ levels. Thus, Ca2+ release into the cytoplasm becomes the earliest evidence of neutrophil stimulation by fMLP and occurs in close association with an apparent membrane hyperpolarization.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
261
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9710-3
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
Simultaneous measurement of stimulus-induced changes in cytoplasmic Ca2+ and in membrane potential of human neutrophils.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.