Linked Life Data

2544849

Source:http://linkedlifedata.com/resource/pubmed/id/2544849

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1989-8-8
pubmed:abstractText
We used [3H]nitrendipine to characterize dihydropyridine sensitive calcium channels on cells isolated from neonatal (1 d) and weanling (11 wk) rabbit gastric fundic and antral smooth muscle. Incubating with and without nifedipine 20 microM, specific binding was 56 +/- 4% of total binding at 0.1 nM [3H]nitrendipine. Specific binding was saturable, reversible, achieved equilibrium by 10 min at 4 degrees C, and was linearly related to cell concentration. The affinity constant for [3H]nitrendipine was higher in weanling fundus (kd = 243 +/- 121 pM) versus antrum (kd = 771 +/- 190 pM), p less than 0.05. There were no age-related changes in affinity. In the antrum, the number of binding sites (Bmax) increased from 6,000 +/- 266/cell in neonates to 27,500 +/- 8,440/cell in weanlings (p less than 0.05). In the fundus Bmax was 7,750 +/- 2,100/cell in neonates, and there was no age-related change. To assess function, we compared isometric stress in full thickness muscle strips oriented to the circular layer. Bethanechol stimulated dose-dependent tonic contractions in the fundus and phasic contractions in the antrum. Maximal stress increased with age from 305 +/- 54 mN/cm2 to 1140 +/- 73 mN/cm2 (p less than 0.05) in the fundus and from 72 +/- 20 mN/cm2 to 154 +/- 30 mN/cm2 (p less than 0.05) in the antrum. Preincubation and incubation without calcium resulted in reversible inhibition of contraction at both ages. Nifedipine 10-microM inhibited 100% of bethanechol-stimulated contraction in the antrum, but only 25% in the fundus at both ages.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0031-3998
pubmed:author
pubmed:issnType
Print
pubmed:volume
25
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
600-4
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Development of calcium channels in gastric smooth muscle.
pubmed:affiliation
Department of Pediatrics, Harbor-UCLA Medical Center, Torrance 90509.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.