In the aorta of prediabetic non-obese diabetic mice, a model of human type 1 diabetes, we investigated gene expression of the endothelin receptors and contractility to big endothelin-1 and endothelin-1 at the ages of 10 and 16 weeks. A subgroup of 10- week-old animals was treated with the endothelin ETA receptor antagonist LU461314 (30 mg/kg per day for 6 weeks). Blood glucose levels were normal in all animals. Real-time polymerase chain reaction analysis revealed that vascular ETB receptor expression was higher in 10-week-old non-obese diabetic (NOD) mice compared with controls. In 16-week-old NOD mice, but not in control mice, ETB receptor mRNA was twofold lower (P < 0.05 vs 10-week-old NOD mice). In all groups ETA receptor expression was unaffected by age or treatment. Contractions to big endothelin-1 and endothelin-1 were lower in 10-week-old NOD mice compared with controls. Treatment with LU461314 increased ETB receptor expression in 16-week-old NOD mice, but had no effect on vascular contractility. These data indicate that dysregulation of ETB receptor expression and a decreased contractile response to big endothelin-1 and endothelin-1 are present in the prediabetic state of a model of human type 1 diabetes. These alterations occur independent of glucose levels. Furthermore, ETA receptor blockade is effective in increasing ETB receptor gene expression, suggesting a potential role for endothelin ETA antagonists in the treatment of type 1 diabetes.
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http://dx.doi.org/10.1097/01.fjc.0000166230.26583.f8 | DOI Listing |
Exp Neurol
December 2024
Department of Medicine, Cardiovascular Research Institute, University of Vermont, Colchester, VT 05446, USA; Department of Neurological Sciences and Neuroscience Graduate Program, University of Vermont, Burlington, VT 05401, USA. Electronic address:
Reciprocal communication between reactive astrocytes and microglial cells provides local, coordinated control over critical processes such as neuroinflammation, neuroprotection, and scar formation after CNS injury, but is poorly understood. The vasoactive peptide hormone endothelin (ET) is released and/or secreted by endothelial cells, microglial cells and astrocytes early after ischemic stroke and other forms of brain injury. To better understand glial cell communication after stroke, we sought to identify paracrine effectors produced and secreted downstream of astroglial endothelin receptor B (ETB) signaling.
View Article and Find Full Text PDFEur J Pharmacol
February 2025
Department of Physiology, School of Medicine, University of Valencia, Spain; Institute of Health Research INCLIVA, Valencia, Spain; Center for Biomedical Research Network on Cardiovascular Diseases (CIBER-CV), Madrid, Spain. Electronic address:
Sympathetic nervous system (SNS), endothelin 1 (ET-1) and angiotensin II (Ang II) are involved in the pathophysiology of acute myocardial infarction (AMI). Valproic acid (VPA) is under study for the treatment against AMI due to its beneficial cardiac effects. However, the vascular effects of VPA on the activation of the SNS, ET-1 and Ang II after AMI are not fully studied.
View Article and Find Full Text PDFACS Chem Biol
December 2024
Department Chemistry and Biochemistry Clemens-Schöpf-Institute, Technical University Darmstadt, Peter-Grünberg Straße 4, Darmstadt 64287, Germany.
Class A G protein-coupled receptors (GPCRs) are key mediators in numerous signaling pathways and important drug targets for several diseases. A major shortcoming in GPCR ligand screening is the detection limit for weak binding molecules, which is especially critical for poorly druggable GPCRs. Here, we present a proximity-based screening system for class A GPCRs, which adopts the natural two-step activation mechanism of class B GPCRs.
View Article and Find Full Text PDFFront Pharmacol
November 2024
Clinical Pharmacology and Quantitative Pharmacology, Clinical Pharmacology and Safety Sciences, R&D, AstraZeneca, Gaithersburg, MD, United States.
Introduction: Endothelin-1 (ET-1) regulates renal and vascular function, but the clinical utility of selective ET receptor antagonists has been limited due to associated fluid retention. The mechanisms underlying fluid retention remain poorly understood but could be a consequence of changes in ET-1 binding to the unantagonized ET receptor, either through increased ET-1 or non-selective ET.
Methods: A mathematical model of ET-1 kinetics was developed to quantify effects of ET antagonist exposure and selectivity on concentrations of ET-1 and its complexes with ET and ET receptors.
Hypertension
December 2024
Research Institute of McGill University Health Centre, Canada (A.C.M., L.L.C., Y.N., S.A.L., R.M.T.).
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