Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1977-3-15
pubmed:abstractText
Four fractions enriched, respectively, in plasma membrane (PM), smooth endoplasmic reticulum (SER), rough endoplasmic reticulum (RER), and mitochondria were isolated from estrogen-dominated rat myometrium. Ca2+ uptake by these fractions was studied in order to estimate the relative potential of the corresponding organelles for controlling intracellular Ca2+ activity. Ca2+ uptake properties of the PM, SER, and RER fractions were similar except that potentiation by oxalate was in the order RER greater than or equal SER greater than PM. However, studies with the ionophores X-537A and A23187 suggested that Ca2+ was transported into the lumen of membrane vesicles of all these fractions. Unlike that of skeletal muscle sarcoplasmic reticulum, Ca2+ uptake by the myometrial fractions was not supported by high-energy compounds other than ATP. Mitochondria took up much less Ca2+ at low, and much more Ca2+ at high, free Ca2+ concentrations than did the other fractions. The amount of Ca2+ taken up in 30 s from a 1 muM free Ca2+ solution in the presence of ATP was similar for all fractions. These results suggested that mitochondria may act as an important Ca2+ control system in rat myometrium when the intracellular Ca2+ concentration is near 1 muM or higher, whereas the PM, SER, and RER may be of major importance at Ca2+ levels of 0.3 muM or lower.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
232
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
C50-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1977
pubmed:articleTitle
Control of intracellular Ca2+ activity in rat myometrium.
pubmed:publicationType
Journal Article