Alpha-Adrenergic Mechanisms in the Cardiovascular Hyperreactivity to Norepinephrine-Infusion in Essential Hypertension.
Front Endocrinol (Lausanne)
; 13: 824616, 2022.
Article
em En
| MEDLINE
| ID: mdl-35937820
ABSTRACT
Aims:
Essential hypertension (EHT) is characterized by cardiovascular hyperreactivity to stress but underlying mechanism are not fully understood. Here, we investigated the role of α-adrenergic receptors (α-AR) in the cardiovascular reactivity to a norepinephrine (NE)-stress reactivity-mimicking NE-infusion in essential hypertensive individuals (HT) as compared to normotensive individuals (NT).Methods:
24 male HT and 24 male NT participated in three experimental trials on three separate days with a 1-min infusion followed by a 15-min infusion. Trials varied in infusion-substances placebo saline (Sal)-infusions (trial-1Sal+Sal), NE-infusion without (trial-2Sal+NE) or with non-selective α-AR blockade by phentolamine (PHE) (trial-3PHE+NE). NE-infusion dosage (5µg/ml/min) and duration were chosen to mimic duration and physiological effects of NE-release in reaction to established stress induction protocols. We repeatedly measured systolic (SBP) and diastolic blood pressure (DBP) as well as heart rate before, during, and after infusions.Results:
SBP and DBP reactivity to the three infusion-trials differed between HT and NT (p's≤.014). HT exhibited greater BP reactivity to NE-infusion alone compared to NT (trial-2-vs-trial-1 p's≤.033). Group differences in DBP reactivity to NE disappeared with prior PHE blockade (trial-3 p=.26), while SBP reactivity differences remained (trial-3 p=.016). Heart rate reactivity to infusion-trials did not differ between HT and NT (p=.73).Conclusion:
Our findings suggest a mediating role of α-AR in DBP hyperreactivity to NE-infusion in EHT. However, in SBP hyperreactivity to NE-infusion in EHT, the functioning of α-AR seems impaired suggesting that the SBP hyperreactivity in hypertension is not mediated by α-AR.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Norepinefrina
/
Adrenérgicos
/
Hipertensão Essencial
Tipo de estudo:
Clinical_trials
Limite:
Humans
/
Male
Idioma:
En
Revista:
Front Endocrinol (Lausanne)
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Alemanha