Linked Life Data

8603497

Source:http://linkedlifedata.com/resource/pubmed/id/8603497

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1996-5-16
pubmed:abstractText
Human pial arteries obtained during surgery frequently exhibit spontaneous periodic contractions. Simultaneous measurements of membrane potential and vessel wall force were used to examine whether these contractions are associated with electrical activity of smooth muscle cells (SMCs). A total of 53 segments from 38 patients were studied, and of these, 26 showed spontaneous contractions related to periodic depolarization and generation of action potentials (APs). The resting membrane potential during the silent periods was -44.0 +/- 0.5 mV. APs without "overshoot'' were observed when spontaneous depolarization reached levels of -40 to -35 mV. Just over half of the arterial segments failed to exhibit spontaneous activity; however, APs could be generated during K+-induced depolarization. The mean SMC resting membrane potential of these vessels was -53.5 +/- 1.5 mV, and this value differed significantly from that of SMCs in spontaneously active arteries. Application of tetrodotoxin did not change the amplitude and duration of APs. Removal of Ca2+ from the bathing solution and addition of nifedipine completely inhibited the spontaneous APs and associated contractions. K+ depolarization failed to induce APs and contraction in the presence of nifedipine. We conclude that periodic spontaneous depolarization and AP generation underlie the periodic spontaneous contractions of human pial arteries. Both the APs and associated contractions are related to the activation of dihydropyridine-sensitive voltage-dependent Ca2+ channels. It is suggested that AP generation can be responsible for vasomotion of human pial arteries in vivo.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0009-7330
pubmed:author
pubmed:issnType
Print
pubmed:volume
78
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
148-53
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Electrical activity underlying rhythmic contraction in human pial arteries.
pubmed:affiliation
A.A. Bogomoletz Institute of Physiology, Ukrainian Academy of Sciences, Kiev, Ukraine.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't