Linked Life Data

1422589

Source:http://linkedlifedata.com/resource/pubmed/id/1422589

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1992-12-18
pubmed:abstractText
1. Relaxant responses to nitroprusside were examined on U46619-contracted pulmonary artery ring preparations from rats exposed to hypoxia, in chambers containing 10% oxygen, for 1, 3, or 14 days, or for 14 days followed by 12 days in room air. Control rats were housed in room air. 2. After 3 days of hypoxia (but not 1 day), rats had elevated pulmonary artery pressure, right ventricular hypertrophy and polycythemia. After 14 days of hypoxia there was, in addition, hypertrophy of the pulmonary artery. In rats returned to room air for 12 days after 14 days of hypoxia, there was still some right ventricular and vascular hypertrophy but no increase in pulmonary artery pressure or polycythemia. 3. The potency (neg log EC50) of nitroprusside on pulmonary arteries taken from rats after 3 or 14 days of hypoxia was significantly less than on preparations from control rats (3 and 11 fold, respectively). This was not seen after 1 day of hypoxia or after 14 days of hypoxia followed by 12 days in room air. Removal of the endothelium from the preparations had no effect on the potency of nitroprusside in control or hypoxic rats (14 days). 4. In preparations from hypoxic, but not control, rats (14 days), the maximum response to nitroprusside was > 100% (177% reversal of the U46619 contraction) in the absence, but not in the presence, of the endothelium, indicating that pulmonary arteries from hypoxic rats had inherent tone which could be counteracted by a relaxing factor from the endothelium. 5. Exposure of rats to hypoxia (14 days) did not affect the potency of nitroprusside on aorta or trachea.6. It is concluded that exposure of rats to hypoxia results in reversible desensitization of the vascular smooth muscle of pulmonary artery to nitroprusside. The time course of this desensitization suggests that it is probably associated with the elevated pulmonary artery pressure or maintained hypoxaemia rather than with the vascular hypertrophy.7. It is postulated that the increase in pulmonary artery pressure and/or the maintained hypoxaemia may cause chronic release of nitric oxide from the pulmonary vascular endothelium or smooth muscle resulting in desensitization of soluble guanylate cyclase to the action of nitroprusside.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/1422589-151344, http://linkedlifedata.com/resource/pubmed/commentcorrection/1422589-1596677, http://linkedlifedata.com/resource/pubmed/commentcorrection/1422589-1724627, http://linkedlifedata.com/resource/pubmed/commentcorrection/1422589-2107090, http://linkedlifedata.com/resource/pubmed/commentcorrection/1422589-2537281, http://linkedlifedata.com/resource/pubmed/commentcorrection/1422589-2817616, http://linkedlifedata.com/resource/pubmed/commentcorrection/1422589-2838598, http://linkedlifedata.com/resource/pubmed/commentcorrection/1422589-2851359, http://linkedlifedata.com/resource/pubmed/commentcorrection/1422589-3025422, http://linkedlifedata.com/resource/pubmed/commentcorrection/1422589-3492925, http://linkedlifedata.com/resource/pubmed/commentcorrection/1422589-3495737, http://linkedlifedata.com/resource/pubmed/commentcorrection/1422589-3654458, http://linkedlifedata.com/resource/pubmed/commentcorrection/1422589-4043223, http://linkedlifedata.com/resource/pubmed/commentcorrection/1422589-443626, http://linkedlifedata.com/resource/pubmed/commentcorrection/1422589-6448017, http://linkedlifedata.com/resource/pubmed/commentcorrection/1422589-6805338, http://linkedlifedata.com/resource/pubmed/commentcorrection/1422589-7285503
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0007-1188
pubmed:author
pubmed:issnType
Print
pubmed:volume
107
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
407-13
pubmed:dateRevised
2010-9-7
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Reduced relaxant potency of nitroprusside on pulmonary artery preparations taken from rats during the development of hypoxic pulmonary hypertension.
pubmed:affiliation
Department of Physiology and Pharmacology, University of Queensland, Brisbane, Australia.
pubmed:publicationType
Journal Article, Comparative Study, In Vitro, Research Support, Non-U.S. Gov't