Linked Life Data

21566016

Source:http://linkedlifedata.com/resource/pubmed/id/21566016

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2011-7-28
pubmed:abstractText
Resting membrane potential (RMP) plays an important role in determining the basal excitability of gastrointestinal smooth muscle. The RMP in colonic muscles is significantly less negative than the equilibrium potential of K(+), suggesting that it is regulated not only by K(+) conductances but by inward conductances such as Na(+) and/or Ca(2+). We investigated the contribution of nonselective cation channels (NSCC) to the RMP in human and monkey colonic smooth muscle cells (SMC) using voltage- and current-clamp techniques. Qualitative reverse transcriptase-polymerase chain reaction was performed to examine potential molecular candidates for these channels among the transient receptor potential (TRP) channel superfamily. Spontaneous transient inward currents and holding currents were recorded in human and monkey SMC. Replacement of extracellular Na(+) with equimolar tetraethylammonium or Ca(2+) with Mn(2+) inhibited basally activated nonselective cation currents. Trivalent cations inhibited these channels. Under current clamp, replacement of extracellular Na(+) with N-methyl-D-glucamine or addition of trivalent cations caused hyperpolarization. Three unitary conductances of NSCC were observed in human and monkey colonic SMC. Molecular candidates for basally active NSCC were TRPC1, C3, C4, C7, M2, M4, M6, M7, V1, and V2 in human and monkey SMC. Comparison of the biophysical properties of these TRP channels with basally active NSCC (bI(NSCC)) suggests that TRPM4 and specific TRPC heteromultimer combinations may underlie the three single-channel conductances of bI(NSCC). In conclusion, these findings suggest that basally activated NSCC contribute to the RMP in human and monkey colonic SMC and therefore may play an important role in determining basal excitability of colonic smooth muscle.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1522-1547
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
301
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
G287-96
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Basally activated nonselective cation currents regulate the resting membrane potential in human and monkey colonic smooth muscle.
pubmed:affiliation
Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, 89557, USA. skoh@medicine.nevada.edu
pubmed:publicationType
Journal Article, In Vitro, Research Support, N.I.H., Extramural