Linked Life Data

8772130

Source:http://linkedlifedata.com/resource/pubmed/id/8772130

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1996-10-8
pubmed:abstractText
Measurements of simultaneous force and intracellular Ca2+ concentration ([Ca2+]i) in rat uterine smooth muscle have been made to elucidate the mechanisms involved when force produced spontaneously, by high-K+ depolarization or carbachol is altered by a change of intracellular pH (pHi). Rises in force and [Ca2+]i were closely correlated for all forms of contraction, with the Ca2+ transient peaking before force. In spontaneously active preparations, alkalinization significantly increased, and acidification decreased, force and [Ca2+]i. Inhibition of the sarcoplasmic reticulum ATPase (cyclopiazonic acid) did not affect these changes, whereas removal of external Ca2+ abolished both responses, suggesting that the effect of pHi is on Ca2+ entry. Alkalinization caused a prolongation of the action potential complex, associated with a potentiation of contractile activity. Acidification produced hyperpolarization and abolition of action potentials and spontaneous activity, but did not prevent brief applications of carbachol or high-K+ from producing depolarization and increasing force, suggesting no impairment of the mechanism of generation of the action potential. For depolarized preparations, acidification increased tonic force and [Ca2+]i; the increase in the calcium signal persisted in zero-external calcium. In the presence of carbachol, acidification transiently increased force and [Ca2+]i, followed by a reduction in both. It is concluded that changes in pHi act at more than one step in excitation-contraction coupling and that changes in [Ca2+]i can account for most of the changes in uterine force.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0031-6768
pubmed:author
pubmed:issnType
Print
pubmed:volume
432
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
803-11
pubmed:dateRevised
2009-9-29
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Stimulus-dependent modulation of smooth muscle intracellular calcium and force by altered intracellular pH.
pubmed:affiliation
Physiological Laboratory, Crown Street, The University of Liverpool, PO Box 147, Liverpool L69 3BX, UK.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't