Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1987-11-19
pubmed:abstractText
Effects of age on the pulmonary vascular responses to histamine (HIST), norepinephrine (NE), 5-hydroxytryptamine (5-HT), and KCl were studied in isolated, perfused lungs from juvenile (7-wk-old), adult (14-wk-old), and mature adult (28-wk-old) normoxic rats and compared with age-matched rats exposed to chronic hypoxia for either 14 or 28 days. Chronic hypoxia changed vasoconstriction to HIST and NE to vasodilation in lungs from juvenile and adult rats. Mature adult lungs only vasoconstricted to these amines in both control and hypoxic animals. Pressor responses to 5-HT were not affected by chronic hypoxia regardless of age group. Pressor responses to KCl were also not altered by hypoxia, but lungs from older rats showed greater control responsiveness to KCl compared with lungs from juveniles. Only lungs from juvenile animals developed significant elevations of base-line resistance as a result of hypoxic exposure. To investigate the contribution of H1-, H2-, and beta-receptors in these changes, we employed chlorpheniramine, metiamide, and propranolol, respectively, as blocking agents in another series of experiments. Chlorpheniramine either reduced vasoconstriction or increased vasodilation to HIST in lungs from both control and hypoxic animals, whereas metiamide was without effect. Propranolol either increased vasoconstriction or reversed vasodilation to HIST and NE in all lungs studied. The present data demonstrate the important interaction between chronic hypoxia and age that can alter pulmonary vascular tone and reactivity. The inverse relationship between age and elevation of pulmonary vascular resistance after chronic hypoxic exposure may be the key element that changes pulmonary vascular reactivity observed during hypoxia.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
8750-7587
pubmed:author
pubmed:issnType
Print
pubmed:volume
63
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1122-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Age-dependent effects of chronic hypoxia on pulmonary vascular reactivity.
pubmed:affiliation
Veterans Administration Medical Center, Northport, New York 11768.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, Non-P.H.S.