Linked Life Data

6731261

Source:http://linkedlifedata.com/resource/pubmed/id/6731261

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1984-7-26
pubmed:abstractText
The efficacy of acute beta blockade in essential hypertension is limited by reflex vasoconstriction. The aim of this study was to determine whether the latter response was modified by prior selective alpha-1-adrenoceptor blockade. A single-blind, within-patient, placebo-controlled evaluation of the immediate hemodynamic effects of sequential alpha-1 (trimazosin)- and beta (propranolol)-adrenoceptor blockade was undertaken in 10 men (34 to 58 years) with previously untreated essential hypertension. The study commenced with a 4-minute control period of constant-load (600 to 900 kpm/min) upright bicycle exercise, and measurements were made before (control) and 30 minutes after intravenous trimazosin (2 mg/kg) and exercise was then repeated; measurements at rest were again made 4 minutes after intravenous propranolol (0.2 mg/kg) before a final exercise period. Trimazosin at rest reduced systolic and diastolic arterial pressure and systemic vascular resistance without change in heart rate, cardiac output, or left ventricular (LV) filling pressure. During upright bicycle exercise the reductions in blood pressure were sustained without change in their rest-to-exercise increments. Other circulatory variables did not differ from control values. At rest the addition of propranolol further reduced systolic arterial pressure. Heart rate and cardiac output fell and systemic vascular resistance increased to its pretreatment control value. During exercise the changes at rest were sustained and the rest-to-exercise increments in blood pressure, heart rate, and cardiac output were reduced. LV filling pressure was significantly increased. In conclusion, alpha-1-adrenoceptor blockade modified the adverse effects of acute beta blockade at rest but not during exercise.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0002-8703
pubmed:author
pubmed:issnType
Print
pubmed:volume
108
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
124-31
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
Rest and exercise hemodynamic effects of sequential alpha-1-adrenoceptor (trimazosin) and beta-adrenoceptor (propranolol) antagonism in essential hypertension.
pubmed:publicationType
Journal Article, Clinical Trial, Controlled Clinical Trial, Research Support, Non-U.S. Gov't