Luis Cassinotti, María Guil, Liliana Bianciotti, Marcelo Vatta
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引用次数: 0
Abstract
Background: We previously reported that endothelins (ETs) regulate tyrosine hydroxylase (TH) activity and expression in the olfactory bulb (OB) of normotensive and hypertensive animals. Applying an ET receptor type A (ETA) antagonist to the brain suggested that endogenous ETs bind to ET receptor type B (ETB) to elicit effects.
Objective: The aim of the present work was to evaluate the role of central ETB stimulation on the regulation of blood pressure (BP) and the catecholaminergic system in the OB of deoxycorticosterone acetate (DOCA)-salt hypertensive rats.
Methods: DOCA-salt hypertensive rats were infused for 7 days with cerebrospinal fluid or IRL-1620 (ETB receptor agonist) through a cannula placed in the lateral brain ventricle. Systolic BP (SBP) and heart rate were recorded by plethysmography. The expression of TH and its phosphorylated forms in the OB were determined by immunoblotting, TH activity by a radioenzymatic assay, and TH mRNA by quantitative real-time polymerase chain reaction.
Results: Chronic administration of IRL-1620 decreased SBP in hypertensive rats but not in normotensive animals. Furthermore, the blockade of ETB receptors also decreased TH-mRNA in DOCA-salt rats, but it did not modify TH activity or protein expression.
Conclusion: These findings suggest that brain ETs through the activation of ETB receptors contribute to SBP regulation in DOCA-salt hypertension. However, the catecholaminergic system in the OB does not appear to be conclusively involved although mRNA TH was reduced. Present and previous findings suggest that in this salt-sensitive animal model of hypertension, the OB contributes to chronic BP elevation.
期刊介绍：
Current Vascular Pharmacology publishes clinical and research-based reviews/mini-reviews, original research articles, letters, debates, drug clinical trial studies and guest edited issues to update all those concerned with the treatment of vascular disease, bridging the gap between clinical practice and ongoing research.
Vascular disease is the commonest cause of death in Westernized countries and its incidence is on the increase in developing countries. It follows that considerable research is directed at establishing effective treatment for acute vascular events. Long-term treatment has also received considerable attention (e.g. for symptomatic relief). Furthermore, effective prevention, whether primary or secondary, is backed by the findings of several landmark trials. Vascular disease is a complex field with primary care physicians and nurse practitioners as well as several specialties involved. The latter include cardiology, vascular and cardio thoracic surgery, general medicine, radiology, clinical pharmacology and neurology (stroke units).
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