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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
2 Pt 2
|
| pubmed:dateCreated |
1993-4-6
|
| pubmed:abstractText |
It is accepted knowledge that the endothelium can profoundly affect vascular tone through the release of vasoactive substances. The maturational changes in the role of the endothelium-derived relaxing factor (EDRF) and ATP-dependent K+ channels in the neonatal pulmonary circulation were investigated in isolated perfused lungs from 1- and 7-day-old piglets. The EDRF inhibitor, N omega-nitro-L-arginine (L-NNA), had potent dose-dependent constrictor effects on the pulmonary vasculature with normal and raised tone. The constrictor effect of L-NNA was greater (P < 0.05) in the 1-day-old than in the 7-day-old lungs and was significantly (P < 0.005) attenuated by pretreatment with the EDRF precursor, L-arginine. Furthermore, we studied the possibility of developmental changes in the sensitivity of smooth muscle cells to EDRF by testing sodium nitroprusside, nitric oxide, and 8-bromoguanosine 3',5'-cyclic monophosphate (8-BrcGMP). All caused a decrease in perfusion pressure, but only sodium nitroprusside elicited a greater (P < 0.01) effect in the 1-day-old. Endothelin-1 (ET-1) and bradykinin (BK) elicited dilator responses that were significantly (P < 0.05) reduced in the presence of L-NNA. Interestingly, the dilator response to ET-1 was more marked (P < 0.001) in the younger group, whereas no age difference was noted with BK. Finally, lemakalim, a K+ channel activator, caused a vasodilation of equal magnitude at both ages. In summary, EDRF and ATP-dependent K+ channels appear to play a role in the control of the newborn piglet pulmonary vasculature.(ABSTRACT TRUNCATED AT 250 WORDS)
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Feb
|
| pubmed:issn |
0002-9513
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
264
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
H302-9
|
| pubmed:dateRevised |
2006-11-15
|
| pubmed:meshHeading |
pubmed-meshheading:8447447-Aging,
pubmed-meshheading:8447447-Animals,
pubmed-meshheading:8447447-Animals, Newborn,
pubmed-meshheading:8447447-Endothelins,
pubmed-meshheading:8447447-Endothelium, Vascular,
pubmed-meshheading:8447447-Nitric Oxide,
pubmed-meshheading:8447447-Potassium Channels,
pubmed-meshheading:8447447-Pulmonary Circulation,
pubmed-meshheading:8447447-Swine,
pubmed-meshheading:8447447-Vasodilation,
pubmed-meshheading:8447447-Vasodilator Agents
|
| pubmed:year |
1993
|
| pubmed:articleTitle |
Maturational changes in endothelium-derived relaxations in newborn piglet pulmonary circulation.
|
| pubmed:affiliation |
Department of Pediatrics, Montreal Children's Hospital, Quebec, Canada.
|
| pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, Non-U.S. Gov't
|