Linked Life Data

11742831

Source:http://linkedlifedata.com/resource/pubmed/id/11742831

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2001-12-14
pubmed:abstractText
Recently, we reported that, whereas in cerebral arteries of the adult a majority of norepinephrine (NE)-induced increase in intracellular Ca2+ concentration ([Ca2+]i) comes from release of the sarcoplasmic reticulum (SR) Ca2+ stores, in the fetus the SR Ca2+ stores are relatively small, and NE-induced increase in [Ca2+]i results mainly from activation of plasma membrane L-type Ca2+ channels (20). In an effort to establish further the role of L-type Ca2+ channels in the developing cerebral arteries, we tested the hypothesis that, in the fetus, increased reliance on plasmalemmal L-type Ca2+ channels is mediated, in part, by increased L-type Ca2+ channel density. We used 3H-labeled (+)isopropyl-4-(2,1,3-benzoxadiazol-4-y1)-1,4-dihydro-(2,6-dimethyl-5-methoxycarbonyl)pyridine-3-carboxylate (PN200-110, isradipine) to measure L-type Ca2+ channel density (Bmax) in the cerebral arteries, common carotid artery (CCA), and descending aortae of fetal (approximately 140 gestation days), newborn (7-10 days), and adult sheep. In the cerebral and common carotid arteries, B(max) values (fmol/mg protein) of fetuses and newborns were significantly greater than those of adults. Western immunoblotting assay also revealed that the density of L-type Ca2+ channel protein in the cerebral arteries and CCA was about twofold greater in the fetus than the adult. Finally, compared with the adult, fetal cerebral arteries demonstrated a significantly greater maximum tension and [Ca2+]i in response to stimulation with the L-type Ca2+ channel agonist Bay K 8644. In addition, Bay K 8644-stimulated fetal vessels demonstrated a maximal tension and [Ca2+]i similar to that observed in response to stimulation with 10(-4) NE. These results support the idea that fetal cerebrovascular smooth muscle relies more on extracellular Ca2+ and L-type Ca2+ channels for contraction than does the adult and that this increased reliance is mediated, in part, by greater L-type Ca2+ channel density. This may have important implications in the regulation of cerebral blood flow in the developing organism.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0363-6119
pubmed:author
pubmed:issnType
Print
pubmed:volume
282
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
R131-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:11742831-3-Pyridinecarboxylic acid..., pubmed-meshheading:11742831-Age Factors, pubmed-meshheading:11742831-Animals, pubmed-meshheading:11742831-Animals, Newborn, pubmed-meshheading:11742831-Aorta, pubmed-meshheading:11742831-Calcium, pubmed-meshheading:11742831-Calcium Channel Agonists, pubmed-meshheading:11742831-Calcium Channel Blockers, pubmed-meshheading:11742831-Calcium Channels, L-Type, pubmed-meshheading:11742831-Cerebral Arteries, pubmed-meshheading:11742831-Cerebrovascular Circulation, pubmed-meshheading:11742831-Immunoblotting, pubmed-meshheading:11742831-Isradipine, pubmed-meshheading:11742831-Muscle, Smooth, Vascular, pubmed-meshheading:11742831-Norepinephrine, pubmed-meshheading:11742831-Radioligand Assay, pubmed-meshheading:11742831-Sheep, pubmed-meshheading:11742831-Tritium, pubmed-meshheading:11742831-Vasoconstriction, pubmed-meshheading:11742831-Vasoconstrictor Agents
pubmed:year
2002
pubmed:articleTitle
L-type Ca2+ channels in fetal and adult ovine cerebral arteries.
pubmed:affiliation
Center for Perinatal Biology, Department of Physiology/Pharmacology, School of Medicine, Loma Linda University, Loma Linda, California 92350, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.