Switch to
Predicate | Object |
---|---|
rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1
|
pubmed:dateCreated |
1982-9-24
|
pubmed:abstractText |
Platelet-activating factor (PAF-acether), a known platelet stimulant and bronchoconstrictor (in vivo), is a potential mediator of inflammation and thrombosis. However, all smooth muscle effects of PAF-acether described to date are indirect, relying upon intravascular platelet activation. Novel actions of PAF-acether and serotonin (5-HT) are presented here; these actions may lead to the development of a practical bioassay for PAF-acether and contribute to the understanding of the mechanism of action for both substances. PAF-acether, when added to a spiral cut guinea-pig trachea suspended in a tissue bath containing Krebs-Henseleit buffer, produced a dose-dependent loss of active tissue tension. The ED50 for this effect of PAF-acether was 75 ng/ml. PAF-acether produced a maximal relaxation which was 68% of that produced by PGE1 and the effect could not be modified by aspirin or propranolol pretreatment. 5-HT, alone, contracted the guinea-pig trachea strip in a dose-dependent manner, but caused relaxation instead when methysergide was present. Aspirin, phenoxybenzamine and propranolol did not alter this loss of active tissue tension. A similar observation was made in vivo using the guinea-pig bronchoconstriction model, in which PAF-acether as well as 5-HT given to methysergide-treated animals caused a decrease in intratracheal pressure. This action of PAF-acether may yield a suitable bioassay method which could facilitate routine measurements of the substance. Furthermore, the similarity in action of PAF-acether and of 5-HT on methysergide-treated animals leads one to speculate about the relationship between the two substances and their mechanism of action in smooth muscle.
|
pubmed:language |
eng
|
pubmed:journal | |
pubmed:citationSubset |
IM
|
pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Acetylcholine,
http://linkedlifedata.com/resource/pubmed/chemical/Aspirin,
http://linkedlifedata.com/resource/pubmed/chemical/Histamine,
http://linkedlifedata.com/resource/pubmed/chemical/Lysophosphatidylcholines,
http://linkedlifedata.com/resource/pubmed/chemical/Methysergide,
http://linkedlifedata.com/resource/pubmed/chemical/Phenoxybenzamine,
http://linkedlifedata.com/resource/pubmed/chemical/Platelet Activating Factor,
http://linkedlifedata.com/resource/pubmed/chemical/Propranolol,
http://linkedlifedata.com/resource/pubmed/chemical/Serotonin
|
pubmed:status |
MEDLINE
|
pubmed:month |
May
|
pubmed:issn |
0014-2999
|
pubmed:author | |
pubmed:issnType |
Print
|
pubmed:day |
7
|
pubmed:volume |
80
|
pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
|
pubmed:pagination |
29-35
|
pubmed:dateRevised |
2006-11-15
|
pubmed:meshHeading |
pubmed-meshheading:7095003-Acetylcholine,
pubmed-meshheading:7095003-Animals,
pubmed-meshheading:7095003-Aspirin,
pubmed-meshheading:7095003-Blood Platelets,
pubmed-meshheading:7095003-Female,
pubmed-meshheading:7095003-Guinea Pigs,
pubmed-meshheading:7095003-Histamine,
pubmed-meshheading:7095003-Lysophosphatidylcholines,
pubmed-meshheading:7095003-Male,
pubmed-meshheading:7095003-Methysergide,
pubmed-meshheading:7095003-Muscle Relaxation,
pubmed-meshheading:7095003-Phenoxybenzamine,
pubmed-meshheading:7095003-Platelet Activating Factor,
pubmed-meshheading:7095003-Propranolol,
pubmed-meshheading:7095003-Serotonin,
pubmed-meshheading:7095003-Trachea
|
pubmed:year |
1982
|
pubmed:articleTitle |
Relaxation of the guinea-pig trachea induced by platelet-activating factor and by serotonin.
|
pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, Non-U.S. Gov't
|