Linked Life Data

3755726

Source:http://linkedlifedata.com/resource/pubmed/id/3755726

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1986-10-20
pubmed:abstractText
This study was designed to examine the role of changes in cytoplasmic free calcium concentration ([Ca2+]i) during the response to alpha 1-adrenergic agonists in cultured renal proximal tubular cells. Experiments were carried out on primary cultures of canine proximal tubular cells grown in defined culture medium on a solid support, on collagen-coated polycarbonate membranes, or on collagen-coated glass coverslips. Quin-2 and fura-2 were used to monitor [Ca2+]i. The basal level of [Ca2+]i was 101 nM, as measured with quin-2, and 122 nM, as determined using fura-2. Fluorescence flow cytometry revealed that about 85% of the population of proximal tubular cells responded to phenylephrine with an increase in [Ca2+]i. Phenylephrine (10(-5) M) caused an immediate actual increase in [Ca2+]i by 18 and 24%, as determined with quin-2 and fura-2, respectively, with the peak increase in [Ca2+]i averaging 22% and 44% over the basal level (180-300 sec). This effect did not require extracellular calcium. The effect of phenylephrine was abolished by prazosin and verapamil. Fluorescence microscopy of quin-2 or fura-2 loaded cells revealed punctate areas of fluorescence within the cytoplasm suggesting vesicular uptake of the dyes. Pinocytotic entrapment of the dyes was demonstrated by the transfer of cell-impermeant fura-2 across tubular cell monolayers mounted in Ussing chambers. The transfer of the dye was similar to that of a marker of fluid-phase pinocytosis, Lucifer Yellow (LY). This pinocytotic entrapment of Ca2+-indicators would lead to underestimation of the actual calcium transients. Microfluorometric study of single proximal tubular cells "scrape-loaded" with fura-2 revealed a four-fold increase in [Ca2+]i concentration following stimulation with phenylephrine.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9541
pubmed:author
pubmed:issnType
Print
pubmed:volume
128
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
466-74
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
Alpha 1-adrenergic stimulation and cytoplasmic free calcium concentration in cultured renal proximal tubular cells: evidence for compartmentalization of quin-2 and fura-2.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't