Linked Life Data

2511995

Source:http://linkedlifedata.com/resource/pubmed/id/2511995

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1990-1-25
pubmed:abstractText
1. Tested against the spontaneous tone of guinea-pig isolated trachealis, cromakalim (0.1-100 microM), isoprenaline (1 nM-1 microM) and theophylline (1 microM-1 mM) each produced concentration-dependent relaxation. 2. Glibenclamide (0.1-10 microM) did not itself alter the spontaneous tone of the trachea nor did it modify the relaxant actions of isoprenaline or theophylline. In contrast, glibenclamide (0.1 and 1 microM) caused a concentration-dependent rightward shift of the log concentration-effect curve of cromakalim. Glibenclamide (10 microM) reduced the slope of the log concentration-effect curve of cromakalim and moved the foot of the curve back towards the control position. 3. Phentolamine (1, 10 and 100 microm) did not itself alter the spontaneous tone of the trachea nor did it modify the relaxant actions of isoprenaline or theophylline. In contrast phentolamine caused concentration-dependent depression of the log concentration-effect curve of cromakalim. 4. Neither prazosin (1 microM) nor yohimbine (10 microM) modified the spontaneous tone of the trachea. Prazosin and yohimbine each failed to antagonise the effects of cromakalim, isoprenaline and theophylline. 5. Intracellular electrophysiological recording showed that glibenclamide (1 microM) and phentolamine (100 microM) caused minor change in the resting membrane potential of trachealis cells. Slow wave activity was slightly depressed by these agents. In contrast tetraethylammonium (TEA; 8 mM) caused marked depolarisation, and promoted the conversion of slow waves into regenerative action potentials. These electrical changes were accompanied by tonic tension development. 6. Phentolamine (100 microM) and glibenclamide (1 microM) reduced and reversed both the relaxation and the hyperpolarisation induced by cromakalim (10 microM). 7. It is concluded that glibenclamide and phentolamine each provide selective antagonism of the relaxant action of cromakalim in guinea-pig trachealis. These agents also inhibit the plasmalemmal hyperpolarisation induced by cromakalim. The effect of phentolamine is unrelated to the blockade of alpha 1- or alpha 2-adrenoceptors. If either glibenclamide or phentolamine act to block the K+ channels opened by cromakalim, then such channels are not identical to those which endow the trachealis plasmalemma with its powerful rectifying behaviour.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/2511995-2415831, http://linkedlifedata.com/resource/pubmed/commentcorrection/2511995-2425082, http://linkedlifedata.com/resource/pubmed/commentcorrection/2511995-2430658, http://linkedlifedata.com/resource/pubmed/commentcorrection/2511995-2445740, http://linkedlifedata.com/resource/pubmed/commentcorrection/2511995-2551442, http://linkedlifedata.com/resource/pubmed/commentcorrection/2511995-2758244, http://linkedlifedata.com/resource/pubmed/commentcorrection/2511995-3072727, http://linkedlifedata.com/resource/pubmed/commentcorrection/2511995-3207991, http://linkedlifedata.com/resource/pubmed/commentcorrection/2511995-6317846, http://linkedlifedata.com/resource/pubmed/commentcorrection/2511995-6871547, http://linkedlifedata.com/resource/pubmed/commentcorrection/2511995-6871556
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0007-1188
pubmed:author
pubmed:issnType
Print
pubmed:volume
98
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
865-74
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Cromakalim-induced relaxation of guinea-pig isolated trachealis: antagonism by glibenclamide and by phentolamine.
pubmed:affiliation
Department of Physiological Sciences, Medical School, University of Manchester.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't