Search results for "aorta"

Role of cyclic nucleotide phosphodiesterase isoenzymes in contractile responses of denuded rat aorta related to various Ca 2+ sources

2001

We have examined the cyclic nucleotide phosphodiesterase isoforms (PDE) involved in the contractile response of rat aorta to different agonists and different experimental procedures for use in functional studies. The inhibitory effect of AAL 05 on the different PDEs isolated from bovine aortic smooth muscle was examined. Compound AAL 05 appeared to be a selective PDE3 inhibitor. We analyzed the ability of the non-selective inhibitor IBMX (3-isobutyl-1-methylxanthine) and the isoenzyme selective inhibitors nimodipine (type 1), AAL 05 (6-(N-methyl-N-cyclohexyl butyl carboxamide) quinolin-2-one) and SKF 94120 (5-(4-acetamidophenyl) pyrazin-2(1H)-one; type3), rolipram (type4) and zaprinast (typ…

No effect of C-reactive protein on early atherosclerosis in LDLR-/- / human C-reactive protein transgenic mice

2008

summaryThe association between increased concentrations of C-reactive protein (CRP) and future cardiovascular events is well established. However, it is currently unclear whether this clinical observation represents an epiphenomenon or whether the pentraxin may actively promote the development of atherosclerosis. Experimental studies with knockout mice with a defect in apolipoprotein E (ApoE-/-) have been used to investigate the role of CRP in atherogenesis, but the results obtained have been contradictory so far. Since knockout mice with a defect in low density lipoprotein receptor (LDLR-/-) may represent a better model of atherogenesis compared to ApoE-/- animals, we undertook experiments…

Cytosolic Ca2+ and Phosphoinositide Hydrolysis Linked to Constitutively Active α1d-Adrenoceptors in Vascular Smooth Muscle

2003

In the present study, we analyzed changes in intracellular Ca2+ levels and inositol phosphate accumulation related to a population of alpha 1d-adrenoceptors in rat aorta resembling constitutively active receptors. Following intracellular Ca2+ store depletion by noradrenaline in Ca2+-free medium and removal of the agonist, restoration of extracellular Ca2+ induced four signals: a biphasic (transient and sustained) increase in [Ca2+]i, inositol phosphate accumulation, and a contractile response in the aorta. The transient increase in Ca2+, the inositol phosphate accumulation, and the contractile response were not observed in aortae incubated with prazosin or BMY 7378 [8-[2-[4-(2-methoxyphenyl…

Polyamines and microbiota in bicuspid and tricuspid aortic valve aortopathy

2019

Polyamines are small aliphatic cationic molecules synthesized via a highly regulated pathway and involved in general molecular and cellular phenomena. Both mammalian cells and microorganisms synthesize polyamines, and both sources may contribute to the presence of polyamines in the circulation. The dominant location for microorganisms within the body is the gut. Accordingly, the gut microbiota probably synthesizes most of the polyamines in the circulation in addition to those produced by the mammalian host cells. Polyamines are mandatory for cellular growth and proliferation. Established evidence suggests that the polyamine spermidine prolongs lifespan and improves cardiovascular health in …

Effects of different agents on the contractile response elicited by extracellular calcium after depletion of internal calcium stores in rat isolated …

1993

Abstract Noradrenaline, 1 μm, induced a sustained contractile response in rat isolated aorta in the presence and in the absence of extracellular Ca2+. After depleting the noradrenaline-sensitive intracellular Ca2+ stores, an increase in the basal tone of the aorta was observed during the incubation period in the presence of Ca2+ and in the absence of the agonist. We have tested the possible pathways through which Ca2+ enters the cell to refill the previously depleted Ca2+ pools, a process that is accompanied by an increase in tension. The magnitude of this increase does not depend on the presence of Mg2+ in the extracellular medium nor on the temperature, suggesting that it is mediated by a…

Local Application of Leptin Antagonist Attenuates Angiotensin II–Induced Ascending Aortic Aneurysm and Cardiac Remodeling

2016

Background Ascending thoracic aortic aneurysm ( ATAA ) is driven by angiotensin II (Ang II ) and contributes to the development of left ventricular ( LV ) remodeling through aortoventricular coupling. We previously showed that locally available leptin augments Ang II ‐induced abdominal aortic aneurysms in apolipoprotein E–deficient mice. We hypothesized that locally synthesized leptin mediates Ang II ‐induced ATAA . Methods and Results Following demonstration of leptin synthesis in samples of human ATAA associated with different etiologies, we modeled in situ leptin expression in apolipoprotein E–deficient mice by applying exogenous leptin on the surface of the ascending aorta. This treatm…

Glycyrrhetinic Acid Reverses the Lipopolysaccharide-Induced Hypocontractility to Noradrenaline in Rat Aorta: Implications to Septic Shock

2014

Abstract.: Septic shock and associated vascular hyporeactivity to vasoconstrictor agonists remain a major problem of critical care medicine. Here we report that glycyrrhetinic acid (GA), the active component of licorice, effectively restores vascular contractility in the model of lipopolysaccharide (LPS)-treated rat aorta. GA was as effective as the NO synthase inhibitor NG-nitroarginine methylester. GA did not affect the vascular NO levels (measured by EPR spin trapping) and relaxations to l-arginine in LPS-treated rings as well as relaxation to S-nitroso-Nacetylpenicillamine in control rings. Thus, GA may represent an interesting alternative to NO synthase inhibitors in sepsis-associated …

a1D-Adrenoceptors are responsible for the high sensitivity and the slow time-course of noradrenaline-mediated contraction in conductance arteries.

2013

The objective of this study was to determine whether the different time-course characteristics of α1-adrenoceptor-mediated contraction in arteries can be related to the subtypes involved. Contractile responses to noradrenaline (NA) were compared with inositol phosphate accumulation and extracellular signal-regulated kinase (ERK)1/2 phosphorylation after α1-agonist stimuli in the same vessels in the presence or absence of α1-antagonists in rat or in α1-subtype knockout (KO) mice. Aorta, where α1D-AR is the main functional subtype, had higher sensitivity to NA (in respect of inositol phosphate [IP], pERK1/2, and contractile response) than tail artery, where the α1A-adrenoceptor subtype is pre…

Apoptosis induced in vascular smooth muscle cells by oxidative stress is partly prevented by pretreatment with CGRP.

2003

Convergent synthesis and preliminary biological evaluations of the stilbenolignan (±)-aiphanol and various congeners

2003

Treatment of an equimolar mixture of stilbene 7 and cinnamyl alcohol 8 with silver carbonate in acetone–benzene afforded a ca. 2 : 1 : 2 : 1 mixture of the stilbenolignan (±)-aiphanol (1) and congeners 2–4 each of which show significant anti-angiogenic and COX-2 inhibitory properties.