Pharmacology of endothelin receptor antagonists ABT-627, ABT-546, A-182086 and A-192621: ex vivo and in vivo studies

2002 ◽  
Vol 103 (s2002) ◽  
pp. 112S-117S ◽  
Author(s):  
Jerry L. WESSALE ◽  
Andrew L. ADLER ◽  
Eugene I. NOVOSAD ◽  
Samuel V. CALZADILLA ◽  
Brian D. DAYTON ◽  
...  
Keyword(s):  
Amino Acid ◽  
Ex Vivo ◽  
In Vivo Studies ◽  
Endothelin Receptor Antagonists ◽  
Endothelin Receptor ◽  
Receptor Antagonists ◽  
Pressor Responses ◽  
Pharmacokinetic Properties ◽  
Isolated Arteries

Endothelins (ETs), 21-amino-acid peptides involved in the pathogenesis of various diseases, bind to ETA and ETB receptors to initiate their effects. Based on the same core structure, we have developed four small-molecule ET receptor antagonists, ABT-627 (atrasentan), ABT-546, A-182086 and A-192621, which exhibit differences in selectivity for ETA and ETB receptors. In this report, we compare the efficacy, potency and pharmacokinetic properties of these four antagonists, including potency in inhibiting ET-1- or Sarafotoxin 6c-induced vessel constriction in isolated arteries and efficacy in antagonizing ET-1-, big ET-1- or Sarafotoxin 6c-induced pressor responses in rats.

Pharmacology of endothelin receptor antagonists ABT-627, ABT-546, A-182086 and A-192621: in vitro studies

2002 ◽  
Vol 103 (s2002) ◽  
pp. 107S-111S ◽  
Author(s):  
J. Ruth WU-WONG ◽  
Douglas B. DIXON ◽  
William J. CHIOU ◽  
Brian K. SORENSEN ◽  
Gang LIU ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Amino Acid ◽  
Small Molecule ◽  
Endothelin Receptor Antagonists ◽  
Endothelin Receptor ◽  
Arachidonic Acid Release ◽  
Functional Responses ◽  
Receptor Antagonists ◽  
Acid Release

Endothelins (ETs), 21-amino-acid peptides involved in the pathogenesis of various diseases, bind to ETA and ETB receptors to initiate their effects. Based on the same core structure, we have developed four small-molecule ET receptor antagonists, ABT-627, ABT-546, A-182086 and A-192621, which exhibit difference in selectivity for ETA and ETB receptors. In this report, we compare the potency and selectivity of these four antagonists in inhibiting 125I-labelled ET-1 binding to cloned human ETA and ETB receptors, and in blocking ET-1-induced functional responses (arachidonic acid release and phosphatidylinositol hydrolysis).

Transfer and Effect of Endothelin Receptor Antagonists in the Human Placenta: an Ex Vivo Perfusion Study of the Isolated Cotyledon

Placenta ◽  
2019 ◽  
Vol 83 ◽  
pp. e53
Author(s):  
Emilie Hitzerd ◽  
Rugina I. Neuman ◽  
Michelle Broekhuizen ◽  
Sinno H.P. Simons ◽  
Sam Schoenmakers ◽  
...  
Keyword(s):  
Human Placenta ◽  
Ex Vivo ◽  
Endothelin Receptor Antagonists ◽  
Endothelin Receptor ◽  
Receptor Antagonists ◽  
Perfusion Study ◽  
Ex Vivo Perfusion

Ex Vivo Inhibition of Platelet Aggregation in Patients with Severe Limb Arteriopathy Treated with BAY U3405, a Specific IX A2 Receptor Antagonist

1994 ◽  
Vol 72 (05) ◽  
pp. 659-662 ◽  
Author(s):  
S Bellucci ◽  
W Kedra ◽  
H Groussin ◽  
N Jaillet ◽  
P Molho-Sabatier ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Ex Vivo ◽  
Randomized Study ◽  
In Vivo Studies ◽  
Walking Distance ◽  
Peripheral Blood Flow ◽  
Walking Ability ◽  
Double Blind ◽  
Platelet Factor

SummaryA double-blind, placebo-controlled randomized study with BAY U3405, a specific thromboxane A2 (TX A2) receptor blocker, was performed in patients suffering from severe stade II limb arteriopathy. BAY U3405 or placebo was administered in 16 patients at 20 mg four times a day (from day 1 to day 3). Hemostatic studies were done before therapy, and on day 2 and day 3 under therapy. On day 3, BAY U3405 was shown to induce a highly statistically significant decrease of the velocity and the intensity of the aggregations mediated by arachidonic acid (56 ± 37% for the velocity, 58 ± 26% for the intensity) or by U46619 endoperoxide analogue (36 ± 35% for the velocity, 37 ± 27% for the intensity). Similar results were already observed on day 2. By contrast, such a decrease was not noticed with ADP mediated platelet aggregation. Furthermore, plasma levels of betathrombo-globulin and platelet factor 4 remained unchanged. Peripheral hemodynamic parameters were also studied. The peripheral blood flow was measured using a Doppler ultrasound; the pain free walking distance and the total walking ability distance were determined under standardized conditions on a treadmill. These last two parameters show a trend to improvement which nevertheless was not statistically significant. All together these results encourage further in vivo studies using BAY U3405 or related compounds on a long-term administration.

Chemical Permeation Enhancers for Transdermal Delivery of Thiocolchicoside: Assessment of Ex-vivo Skin Flux and In-vivo Pharmacokinetics

2017 ◽  
Vol 10 (5) ◽  
pp. 3827-3835
Author(s):  
Y Madhusudan Rao ◽  
Gayatri P ◽  
Ajitha M ◽  
P. Pavan Kumar ◽  
Kiran kumar
Keyword(s):  
Passive Control ◽  
Ex Vivo ◽  
Skin Permeation ◽  
In Vivo Studies ◽  
Permeation Enhancers ◽  
Casting Technique ◽  
Chemical Permeation Enhancers ◽  
Chemical Permeation ◽  
In Vivo Pharmacokinetics

Present investigation comprises the study of ex-vivo skin flux and in-vivo pharmacokinetics of Thiocolchicoside (THC) from transdermal films. The films were fabricated by solvent casting technique employing combination of hydrophilic and hydrophobic polymers. A flux of 18.08 µg/cm2h and 13.37µg/cm2h was achieved for optimized formulations containing 1, 8-cineole and oleic acid respectively as permeation enhancers. The observed flux values were higher when compared to passive control (8.66 µg/cm2h). Highest skin permeation was observed when 1,8-cineole was used as chemical permeation enhancer and it considerably (2-2.5 fold) improved the THC transport across the rat skin. In vivo studies were performed in rabbits and samples were analysed by LC-MS-MS. The mean area under the curve (AUC) values of transdermal film showed about 2.35 times statistically significant (p<0.05) improvement in bioavailability when compared with the oral administration of THC solution. The developed transdermal therapeutic systems using chemical permeation enhancers were suitable for drugs like THC in effective management of muscular pain.    

Monocytes as Carriers of Magnetic Nanoparticles for Tracking Inflammation in the Epileptic Rat Brain

2019 ◽  
Vol 16 (7) ◽  
pp. 637-644 ◽  
Author(s):  
Hadas Han ◽  
Sara Eyal ◽  
Emma Portnoy ◽  
Aniv Mann ◽  
Miriam Shmuel ◽  
...  
Keyword(s):  
Brain Tissue ◽  
Ex Vivo ◽  
In Vivo Studies ◽  
Nanoparticle Distribution ◽  
Spontaneous Seizures ◽  
Systemic Distribution ◽  
Hippocampal Ca1 ◽  
Pilocarpine Model

Background: Inflammation is a hallmark of epileptogenic brain tissue. Previously, we have shown that inflammation in epilepsy can be delineated using systemically-injected fluorescent and magnetite- laden nanoparticles. Suggested mechanisms included distribution of free nanoparticles across a compromised blood-brain barrier or their transfer by monocytes that infiltrate the epileptic brain. Objective: In the current study, we evaluated monocytes as vehicles that deliver nanoparticles into the epileptic brain. We also assessed the effect of epilepsy on the systemic distribution of nanoparticleloaded monocytes. Methods: The in vitro uptake of 300-nm nanoparticles labeled with magnetite and BODIPY (for optical imaging) was evaluated using rat monocytes and fluorescence detection. For in vivo studies we used the rat lithium-pilocarpine model of temporal lobe epilepsy. In vivo nanoparticle distribution was evaluated using immunohistochemistry. Results: 89% of nanoparticle loading into rat monocytes was accomplished within 8 hours, enabling overnight nanoparticle loading ex vivo. The dose-normalized distribution of nanoparticle-loaded monocytes into the hippocampal CA1 and dentate gyrus of rats with spontaneous seizures was 176-fold and 380-fold higher compared to the free nanoparticles (p<0.05). Seizures were associated with greater nanoparticle accumulation within the liver and the spleen (p<0.05). Conclusion: Nanoparticle-loaded monocytes are attracted to epileptogenic brain tissue and may be used for labeling or targeting it, while significantly reducing the systemic dose of potentially toxic compounds. The effect of seizures on monocyte biodistribution should be further explored to better understand the systemic effects of epilepsy.

Phenolic Acids Exert Anticholinesterase and Cognition-Improving Effects

2018 ◽  
Vol 15 (6) ◽  
pp. 531-543 ◽  
Author(s):  
Dominik Szwajgier ◽  
Ewa Baranowska-Wojcik ◽  
Kamila Borowiec
Keyword(s):  
Phenolic Acids ◽  
Ex Vivo ◽  
Amyloid Β ◽  
Inhibitory Effect ◽  
In Vivo Studies ◽  
Amyloid Β Peptide ◽  
Beneficial Effects ◽  
Aβ Fibrils

Numerous authors have provided evidence regarding the beneficial effects of phenolic acids and their derivatives against Alzheimer's disease (AD). In this review, the role of phenolic acids as inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) is discussed, including the structure-activity relationship. In addition, the inhibitory effect of phenolic acids on the formation of amyloid β-peptide (Aβ) fibrils is presented. We also cover the in vitro, ex vivo, and in vivo studies concerning the prevention and treatment of the cognitive enhancement.

Development, Pre-clinical Investigation and Histopathological Evaluation of Metronidazole Loaded Topical Formulation for Treatment of Skin Inflammatory disorders

2020 ◽  
Vol 10 ◽  
Author(s):  
Divya Thakur ◽  
Gurpreet Kaur ◽  
Sheetu Wadhwa ◽  
Ashana Puri
Keyword(s):  
Ex Vivo ◽  
Clinical Investigation ◽  
In Vivo Studies ◽  
Tween 20 ◽  
Inflammatory Disorders ◽  
Rat Paw Edema ◽  
Ex Vivo Permeation ◽  
Permeation Studies ◽  
Anti Inflammatory

Background: Metronidazole (MTZ) is an anti-oxidant and anti-inflammatory agent with beneficial therapeutic properties. The hydrophilic nature of molecule limits its penetration across the skin. Existing commercial formulations have limitations of inadequate drug concentration present at target site, which requires frequent administration and poor patient compliance. Objective: The aim of current study was to develop and evaluate water in oil microemulsion of Metronidazole with higher skin retention for treatment of inflammatory skin disorders. Methods: Pseudo ternary phase diagrams were used in order to select the appropriate ratio of surfactant and co-surfactant and identify the microemulsion area. The selected formulation consisted of Capmul MCM as oil, Tween 20 and Span 20 as surfactant and co-surfactant, respectively, and water. The formulation was characterized and evaluated for stability, Ex vivo permeation studies and in vivo anti-inflammatory effect (carrageenan induced rat paw edema, air pouch model), anti-psoriatic activity (mouse-tail test). Results: The particle size analyses revealed average diameter and polydispersity index of selected formulation to be 16 nm and 0.373, respectively. The results of ex vivo permeation studies showed statistically higher mean cumulative amount of MTZ retained in rat skin from microemulsion i.e. 21.90 ± 1.92 μg/cm2 which was 6.65 times higher as compared to Marketed gel (Metrogyl gel®) with 3.29 ± 0.11 μg/cm2 (p<0.05). The results of in vivo studies suggested the microemulsion based formulation of MTZ to be similar in efficacy to Metrogyl gel®. Conclusion: Research suggests efficacy of the developed MTZ loaded microemulsion in treatment of chronic skin inflammatory disorders.

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