Linked Life Data

1868983

Source:http://linkedlifedata.com/resource/pubmed/id/1868983

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1991-9-17
pubmed:abstractText
Histamine stimulation of swine arterial smooth muscle is associated with a high [Ca2+]i sensitivity for increases in myosin light-chain phosphorylation. In contrast, KCl depolarization produces a relatively lower [Ca2+]i sensitivity (i.e., similar increases in [Ca2+]i induce less myosin phosphorylation). We evaluated whether 1) artifacts in the methodology for measuring [Ca2+]i or 2) true alterations in the [Ca2+]i sensitivity of myosin light-chain kinase were responsible for these apparent changes in the [Ca2+]i sensitivity of phosphorylation. The [Ca2+]i sensitivity of phosphorylation was higher with histamine stimulation regardless of whether the [Ca2+]i indicator was aequorin (which was loaded intracellularly by reversible hyperpermeabilization) or Fura 2 (which was loaded intracellularly by incubation of the tissues in Fura 2 AM). Aequorin and Fura 2 appeared to detect qualitatively similar stimulus-induced changes in [Ca2+]i with the exception that the initial response to histamine stimulation was different (histamine initially induced a large aequorin light transient and a relatively smaller increase in Fura 2 fluorescence). The [Ca2+]i sensitivity of myosin light-chain kinase extracted from KCl depolarized tissues was lower than the [Ca2+]i sensitivity of myosin light-chain kinase extracted from unstimulated or histamine stimulated tissues. These results suggest that depolarization specifically modifies myosin light-chain kinase to decrease its [Ca2+]i sensitivity. Changes in the [Ca2+]i sensitivity of myosin light-chain phosphorylation are not an artifact of the [Ca2+]i measurement technique.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0892-6638
pubmed:author
pubmed:issnType
Print
pubmed:volume
5
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2593-9
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Depolarization decreases the [Ca2+]i sensitivity of myosin light-chain kinase in arterial smooth muscle: comparison of aequorin and fura 2 [Ca2+]i estimates.
pubmed:affiliation
Department of Internal Medicine, University of Virginia Health Science Center, Charlottesville 22908.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't