Linked Life Data

2354501

Source:http://linkedlifedata.com/resource/pubmed/id/2354501

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2-3
pubmed:dateCreated
1990-7-26
pubmed:abstractText
A rise in cytosolic free Ca2+ is the immediate trigger for contraction in vascular smooth muscle (VSM). We employed the fluorescent Ca2(+)-indicator, Fura-2, and digital imaging microscopy to study the spatial distribution of intracellular Ca2+ in cultured A7r5 cells and the changes evoked by activation with 5-HT. Several methodological considerations that affect the temporal and spatial resolution of Ca2+ images have been addressed. These include: cytoplasmic distribution of Fura-2, wavelength selection for ratio imaging, signal:noise ratio measurement and the effect of [Ca2+] on the limits of detectability under conditions in which [Ca2+] is changing. The distribution of apparent free Ca2+, [Ca2+]App, in A7r5 cells was heterogeneous. This reflects, in part, different pools of intracellular Ca2+. [Ca2+]App was lowest in the nucleus (113 +/- 14 nM; n = 20 cells) and highest in the organelle-rich perinuclear region (228 +/- 12; n = 20), while the surrounding cytoplasmic area (containing relatively few organelles) had intermediate [Ca2+]app levels (150 +/- 13; n = 20). 5-HT (1 microM) evoked transient increases in [Ca2+]App that began within 11 s as relatively modest elevations of [Ca2+]App in the periphery, near the sarcolemma, and subsequently spread to the entire cell, reaching a peak within 18-24 s. At the peak of the Ca2+ transients, [Ca2+]App was highest in the perinuclear region where it sometimes exceeded the maximal detectable levels of the system (1.9 microM). The average peak Ca2+ transient amplitude in the non-nuclear cytoplasm was 1083 +/- 208 nM (1 microM 5-HT; n = 20 cells). Despite the continued presence of 5-HT following the Ca2+ transients, [Ca2+]App then returned to pre-stimulation levels within 5 min. These observations indicate that digital imaging microscopy enables the study of subcellular regulation of intracellular Ca2+ in VSM. The results provide new insights into the role of localized changes in Ca2+ in the regulation of VSM contractility.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0143-4160
pubmed:author
pubmed:issnType
Print
pubmed:volume
11
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
221-31
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:articleTitle
Measurement of intracellular Ca2+ in cultured arterial smooth muscle cells using Fura-2 and digital imaging microscopy.
pubmed:affiliation
Department of Physiology, University of Maryland School of Medicine, Baltimore.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't