Linked Life Data

6177934

Source:http://linkedlifedata.com/resource/pubmed/id/6177934

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1982-8-26
pubmed:abstractText
Aging has been reported to alter the responsiveness of beta-receptors, but there have been few comparable studies of alpha-receptors. This study compares in six young and six healthy elderly subjects the haemodynamic effects of the alpha 1 -antagonist prazosin and the pressor responses to the alpha 1-agonist phenylephrine. Prazosin orally lowered erect (but not supine) blood pressure in both groups by a similar amount between 2 and 6 h after dosing. Maximal falls in systolic pressure were 19.5 +/- 15.7 and 29.3 +/- 11.4 mm Hg (mean +/- SD) in young and old, respectively. There was a significant difference in the associated heart rate response: in the young group mean heart rate increased to 103 beats/min, but there was no corresponding increase in the elderly group, which has a mean heart rate of 80 beats/min. Following the intravenous infusion of increasing doses of phenylephrine, log dose-response curves were deprived, and the dose required to raise mean arterial pressure by 20 mm Hg (PD20) was compared. The mean PD20 was significantly different in the two groups: 2.5 +/- 1.6 in the young, compared to 4.6 +/- 2.3 micrograms/kg/min in the elderly. However, no significant difference was apparent when pressor responsiveness was determined following the administration of prazosin. Thus, while there is no evidence of an age-related increase in the sensitivity of alpha-adrenoceptor-mediated vasoconstriction, the data are not inconsistent with an age-related reduction in responsiveness to alpha-adrenoceptor activation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0160-2446
pubmed:author
pubmed:issnType
Print
pubmed:volume
4
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
388-92
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:articleTitle
Effect of age on the responsiveness of vascular alpha-adrenoceptors in man.
pubmed:publicationType
Journal Article