Identification of higenamine as a novel α1 -adrenergic receptor antagonist.
Phytother Res
; 33(3): 708-717, 2019 Mar.
Article
em En
| MEDLINE
| ID: mdl-30648306
ABSTRACT
The α1 -adrenoceptor (α1 -AR) antagonists are potential candidates for the treatment of blood pressure. Higenamine (HG) is a novel α1 -AR antagonist. In this study, we investigated the effects of HG in HEK293A cells transfected with α1A -, α1B -, and α1D -AR in vitro, rat mesenteric artery ex vivo, Wistar-Kyoto rats and spontaneously hypertensive rats in vivo. The radioligand binding assay showed that HG competitively inhibited the binding of [3 H]-prazosin to α1 -AR in a concentration-dependent manner. The affinities (pKi) of HG for the cloned α1A -, α1B -, and α1D -AR were 6.57, 6.48, and 6.35, respectively, indicating that HG displayed no selectivity for the three α1 -AR subtypes. In in vitro studies, HG was able to blunt inositol monophosphate production. It also displayed an inhibitory effect on the influx and entry of calcium ions and phosphorylation of extracellular signal-regulated kinase 1 and 2 induced by phenylephrine (PE). In ex vivo studies, PE caused a dose-dependent inotropic response curve, and the pA2 value for HG was 6.86 ± 0.29. In addition, the in vivo results showed that HG could decrease the blood pressure in normotension, spontaneous hypertension, and PE-induced hypertension models. These results indicate that HG can directly bind to α1 -AR and it appears to be a novel antagonist for α1 -AR, which may contribute to its hypotensive effect.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tetra-Hidroisoquinolinas
/
Alcaloides
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Antagonistas de Receptores Adrenérgicos alfa 1
Tipo de estudo:
Diagnostic_studies
Limite:
Animals
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Humans
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Male
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article