The impaired fibrinolytic capacity in hypertension is unaffected by acute blood pressure lowering.
J Thromb Thrombolysis
; 32(4): 399-404, 2011 Nov.
Article
em En
| MEDLINE
| ID: mdl-21614456
ABSTRACT
The endogenous fibrinolytic system and the ability of the endothelium to release tissue-plasminogen activator (t-PA) play a pivotal role to protect humans from atherothrombotic events. We have recently reported that the decreased capacity for t-PA release in hypertension is restored with chronic blood pressure lowering. Thus, we explored if acute blood pressure lowering has the same effect. The capacity for acute t-PA release was investigated in the perfused-forearm model during stimulation by intra-arterial substance P 8 pmol/min in hypertensive subjects. The procedure was then repeated during acute blood pressure lowering (n = 9) induced by sodium nitroprusside (SNP) infusion or during placebo infusion (n = 3). SNP lowered mean arterial pressure from 108.6 (2.6) to 83.0 (2.6) (mean and SEM) mmHg (P < 0.001). Substance P induced significant increase in t-PA release during both high- and low-pressure conditions (P < 0.01, ANOVA). Peak t-PA release rate was 199 (77) and 167 (41) (mean and SEM) ng/min/l tissue, and accumulated t-PA release was 2,395 (750) and 2,394 (473) ng, during high- and low-pressure conditions, respectively. t-PA release and hemodynamic responses were almost identical during high- and low-pressure conditions (P = ns, for all). Acute blood pressure lowering does not restore stimulated t-PA release from the endothelium in hypertensive subjects. These findings are in contrast to previously described effects of chronic blood pressure treatment. Although data need to be confirmed in a larger study, they suggest that high blood pressure decreases the cellular t-PA pool rather than interferes with release mechanisms of the protein.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Pressão Sanguínea
/
Ativador de Plasminogênio Tecidual
/
Fibrinólise
/
Hipertensão
Tipo de estudo:
Clinical_trials
/
Prognostic_studies
Limite:
Humans
/
Middle aged
Idioma:
En
Revista:
J Thromb Thrombolysis
Assunto da revista:
ANGIOLOGIA
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Suécia