Document Detail


Tissue-type plasminogen activator release in healthy subjects and hypertensive patients: relationship with beta-adrenergic receptors and the nitric oxide pathway.
MedLine Citation:
PMID:  18574075     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The relationship between adrenergic stimuli and NO in modulating tissue-type plasminogen activator (t-PA) release from endothelial cells was investigated in normotensive subjects and essential hypertensive patients. Sympathetic activation, a well-known stimulus for endogenous fibrinolysis, is also involved in the determination of cardiovascular risk in essential hypertension. However, the existence of cross-talk between adrenergic stimuli and NO availability in modulating t-PA release is not well established yet. We assessed the release of t-PA in the forearm microcirculation of 58 normotensive subjects (mean age: 47+/-9 years) and 44 essential hypertensive patients (mean age: 48+/-11 years) under specific intra-arterial adrenergic stimuli. Intrabrachial infusion of epinephrine (0.1 to 0.3 microg/100 mL per minute) induced greater t-PA release in normotensive subjects as compared with essential hypertensive patients (P<0.05). However, inhibition of NO synthase with N(G)-monomethyl-L-arginine (100 microg/100 mL per minute) infusion blunted epinephrine-induced t-PA release in normotensive subjects (P<0.05) but not in essential hypertensive patients. In normotensive subjects, t-PA release by epinephrine was not affected by phentolamine (8 microg/100 mL per minute) coinfusion and was abolished in the presence of propanolol (10 microg/100 mL per minute). Intrabrachial isoproterenol (0.03 microg/100 mL per minute) induced a significant increase in t-PA release (P<0.01), an effect blunted by N(G)-monomethyl-L-arginine (P<0.05). In essential hypertensive patients, the response to isoproterenol was impaired as compared with normotensive subjects and was unaffected by N(G)-monomethyl-L-arginine coinfusion. In conclusion, the results of the present study demonstrate that adrenergic-induced t-PA release is mediated by beta-adrenoreceptors via a mechanism involving the NO pathway. Our results show an impaired adrenergic-stimulated t-PA release among essential hypertensive patients, probably mediated via a reduced NO availability. This impaired fibrinolytic activity might contribute to the increased cardiovascular risk associated with hypertension.
Authors:
Chiara Giannarelli; Agostino Virdis; Ferdinando De Negri; Emiliano Duranti; Armando Magagna; Lorenzo Ghiadoni; Antonio Salvetti; Stefano Taddei
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Publication Detail:
Type:  Journal Article     Date:  2008-06-23
Journal Detail:
Title:  Hypertension     Volume:  52     ISSN:  1524-4563     ISO Abbreviation:  Hypertension     Publication Date:  2008 Aug 
Date Detail:
Created Date:  2008-07-24     Completed Date:  2008-08-22     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  7906255     Medline TA:  Hypertension     Country:  United States    
Other Details:
Languages:  eng     Pagination:  314-21     Citation Subset:  IM    
Affiliation:
Department of Internal Medicine, University of Pisa, Via Roma, 67, 56100 Pisa, Italy. c.giannarelli@int.med.unipi.it
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MeSH Terms
Descriptor/Qualifier:
Adult
Aged
Analysis of Variance
Case-Control Studies
Epinephrine / pharmacology
Female
Humans
Hypertension / blood*,  diagnosis
Infusions, Intra-Arterial
Male
Middle Aged
Nitric Oxide / metabolism*
Probability
Receptors, Adrenergic, beta / analysis,  metabolism*
Reference Values
Sensitivity and Specificity
Signal Transduction / drug effects,  physiology
Tissue Plasminogen Activator / analysis,  metabolism*
Chemical
Reg. No./Substance:
0/Receptors, Adrenergic, beta; 10102-43-9/Nitric Oxide; 51-43-4/Epinephrine; EC 3.4.21.68/Tissue Plasminogen Activator
Comments/Corrections
Comment In:
Hypertension. 2008 Aug;52(2):218-9   [PMID:  18574069 ]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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