Linked Life Data

9049160

Source:http://linkedlifedata.com/resource/pubmed/id/9049160

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1997-6-10
pubmed:abstractText
In smooth muscle cells freshly isolated from the bovine ciliary body, effects of carbachol (CCh) on the membrane potential and current were examined by the whole-cell clamp method. The resting membrane potential of the muscle cells used was -60 +/- 1 mV (n = 111). Extracellular application of CCh (2 microM) depolarized the cells to -15 +/- 5 mV (n = 50) with an apparent increase in membrane conductance. Under voltage-clamp conditions, CCh (2 microM) evoked an inward current which exhibited inward-going rectification and reversed the polarity at about 0 mV. Removal of Na+ from the external solution caused a reduction of the amplitude of the current and a shift of the reversal potential to the negative direction. CCh was able to elicit an inward current even under a condition where Ca2+ was the only cation producing an inwardly directed electrochemical gradient. The current was not affected by verapamil or by tetrodotoxin. The CCh-induced current was inhibited by antimuscarinic agents with the affinity sequence: atropine approximately 4-DAMP > > pirenzepine > AF-DX116, indicating that the response is mediated by a muscarinic cholinoceptor that belongs to the M3-subtype. Unlike the non-selective cation channel current in intestinal smooth muscles, which is activated by elevation of the intracellular Ca2+ concentration ([Ca2+]i), the current of the ciliary muscle was inactivated when the [Ca2+]i was increased. The conductance, which admits Ca2+, may serve as a pathway for Ca2+ entry required for contraction.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0031-6768
pubmed:author
pubmed:issnType
Print
pubmed:volume
433
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
705-12
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Activation of non-selective cation conductance by carbachol in freshly isolated bovine ciliary muscle cells.
pubmed:affiliation
Department of Ophthalmology, School of Medicine, Nagoya University, Japan.
pubmed:publicationType
Journal Article, In Vitro