Linked Life Data

17880368

Source:http://linkedlifedata.com/resource/pubmed/id/17880368

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2007-9-20
pubmed:abstractText
1. In guinea-pig taenia caeci smooth muscle we have found that 10(-4) mol/L carbachol-induced desensitization to muscarinic agonists develops within 15-30 s, followed by transient resensitization at 1 min, whereas the desensitization to depolarizing high K(+) develops with maximal desensitization at 1 min followed by sustained resensitization up to 30 min. In both cases, Ca(2+)-dependent processes play a crucial role in determining the development of desensitization. 2. To elucidate whether these peculiar processes of desensitization/resensitization may be induced by a lower concentration of carbachol, we examined the development of desensitization induced by 10(-6) mol/L carbachol, because at this concentration carbachol is known to induce biphasic changes in intracellular Ca(2+) concentrations, with a smaller transient increase followed by a larger sustained increase than seen with 10(-4) mol/L carbachol. 3. Contractile responses to muscarinic agonists (carbachol or AHR-602) and high K(+) were desensitized by pretreatment with 10(-6) mol/L carbachol for 30 min in a manner dependent on the presence of extracellular Ca(2+). 4. The development of 10(-6) mol/L carbachol-induced desensitization to these muscarinic agonists in the presence of extracellular Ca(2+) showed three successive phases: fast desensitization within 30 s, followed by transient resensitization at 1 min and the subsequent development of desensitization up to 30 min. In contrast, desensitization to high K(+) did not develop up to 10 min and significant desensitization occurred at 30 min, with no apparent resensitization phase. 5. These results suggest that the characteristics of the Ca(2+)-dependent development of desensitization to muscarinic agonists, but not to high K(+), are well maintained in desensitization induced by a lower concentration of carbachol.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0305-1870
pubmed:author
pubmed:issnType
Print
pubmed:volume
34
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1145-50
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Desensitization of guinea-pig taenia caeci smooth muscle induced by a low concentration of carbachol.
pubmed:affiliation
Department of Pharmacodynamics, Meiji Pharmaceutical University, Tokyo, Japan. hishi@my-pharm.ac.jp
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't