Linked Life Data

1761505

Source:http://linkedlifedata.com/resource/pubmed/id/1761505

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1992-2-7
pubmed:abstractText
The vascular response to the muscarinic receptor agonist acetylcholine (ACh) in the presence of selected antagonists was examined in the isolated blood-perfused canine left lower lung lobe under conditions of normal (resting) and elevated vascular tone. At normal vascular tone, ACh (1-5 mumol) produced a dose-dependent increase in pulmonary arterial pressure (Ppa), total pulmonary vascular resistance (PVR), and downstream resistance (Rds) without altering upstream resistance (Rus). Pirenzepine (50 and 100 nM), the prototype M1-selective antagonist, and gallamine, an M2-selective antagonist, as well as atropine (50 nM) and secoverine (100 nM), nonselective antagonists, attenuated (P less than 0.05) the ACh-induced increase in Ppa and Rds. With elevated vascular tone induced by serotonin infusion, ACh produced a dose-dependent increase in Ppa in 19 of 25 lobes, although Rus decreased while Rds increased in all lobes. At high vascular tone, pirenzepine or gallamine attenuated the ACh-induced increase in Rds, whereas Rus was not affected. Secoverine and atropine antagonized ACh-induced increases in both Rds and Rus. The pA2 values (i.e., the negative log antagonist concentration requiring a doubling of ACh dose for an equivalent increase in Rds) for gallamine, pirenzepine, secoverine, and atropine were 6.1 +/- 0.1, 7.4 +/- 0.1, 8.3 +/- 0.2, and 10.2 +/- 0.3, respectively. These results suggest that 1) ACh increases PVR in the dog by constricting the venous segments (downstream) of the pulmonary circulation via activation of pulmonary vascular muscarinic receptors under conditions of both normal and elevated vascular tone, 2) both M1- and non-M1-muscarinic receptor subtypes appear to participate in mediating the ACh-induced increase in Rds, and 3) ACh moderately relaxes the upstream (arterial) vessels, especially under conditions of elevated tone.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
8750-7587
pubmed:author
pubmed:issnType
Print
pubmed:volume
71
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2032-43
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Multiple muscarinic receptor subtypes in the canine pulmonary circulation.
pubmed:affiliation
Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta 30912.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't