Linked Life Data

497522

Source:http://linkedlifedata.com/resource/pubmed/id/497522

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1980-1-19
pubmed:abstractText
1 In the isolated, lumen-perfused, stomach preparation of the mouse, metiamide was found by kinetic analysis to behave like a simple competitive antagonist of histamine-stimulated acid secretion. However, the pK(B) estimate of 5.08 was significantly lower than that found in guinea-pig atrium (6.0) or rat uterus (6.1) suggesting that H(2)-receptors might not be homogeneous.2 A similar analysis showed that atropine also behaved like a simple competitive antagonist of bethanechol-stimulated acid secretion and the estimated pK(B) (7.65) was significantly lower than the standard estimate of this parameter in guinea-pig ileum (9.0). Either the muscarinic cholinoceptors in mouse stomach were also anomalous or the preparation was introducing a systematic error. Lumen perfusion might distort this type of kinetic analysis by allowing steady-state conditions but not true equilibrium to develop at the receptor compartment due to loss of antagonist into the gastric secretion. Drug interactions at receptors in the muscle layers of the stomach would be expected to be much less sensitive to this error.3 When the atropine-bethanechol interaction was measured on the contraction of the isolated, lumen-perfused, stomach of the mouse the necessary conditions for simple competition were not met even though the sensitivity to atropine was obviously increased. The criteria for the expected simple competition were being obscured by events at low antagonist concentrations. Alterations in agonist or antagonist concentrations could be more or less eliminated so that physiological antagonism, perhaps by release of 5-hydroxytryptamine, was considered. This was supported, to some extent, by finding that, when stomachs from animals pretreated with reserpine were used, the kinetic analysis was normalized and gave a pK(B) of 8.99. Apparently, the muscarinic receptors in mouse stomach are homogeneous with those in other tissues.4 Therefore, we conclude that our results no more point to heterogeneity among histamine receptors than they point to differences in muscarinic cholinoceptors because this type of kinetic analysis can be readily distorted by special features of the measuring system.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/497522-1129340, http://linkedlifedata.com/resource/pubmed/commentcorrection/497522-13651579, http://linkedlifedata.com/resource/pubmed/commentcorrection/497522-188329, http://linkedlifedata.com/resource/pubmed/commentcorrection/497522-188469, http://linkedlifedata.com/resource/pubmed/commentcorrection/497522-4148625, http://linkedlifedata.com/resource/pubmed/commentcorrection/497522-4205, http://linkedlifedata.com/resource/pubmed/commentcorrection/497522-4401751, http://linkedlifedata.com/resource/pubmed/commentcorrection/497522-4538093, http://linkedlifedata.com/resource/pubmed/commentcorrection/497522-4984998, http://linkedlifedata.com/resource/pubmed/commentcorrection/497522-5497803, http://linkedlifedata.com/resource/pubmed/commentcorrection/497522-5566763, http://linkedlifedata.com/resource/pubmed/commentcorrection/497522-5639114, http://linkedlifedata.com/resource/pubmed/commentcorrection/497522-5772742, http://linkedlifedata.com/resource/pubmed/commentcorrection/497522-5951570, http://linkedlifedata.com/resource/pubmed/commentcorrection/497522-621277, http://linkedlifedata.com/resource/pubmed/commentcorrection/497522-922255
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0007-1188
pubmed:author
pubmed:issnType
Print
pubmed:volume
67
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
59-65
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
1979
pubmed:articleTitle
Analysis of anomalous pKb values for metiamide and atropine in the isolated stomach of the mouse.
pubmed:publicationType
Journal Article