Catecholamines Abrogate the Anti-Mitogenic Effects of 2-Hydroxy Metabolite of Estradiol on Vascular Smooth Muscle Cells by Inhibiting Catechol-O-Methyltransferase (COMT) Activity and 2-Methoxyestradiol Formation

Hypertension ◽  
2000 ◽  
Vol 36 (suppl_1) ◽  
pp. 705-706
Author(s):  
Lefteris C Zacharia ◽  
Edwin K Jackson ◽  
Delbert G Gillespie ◽  
Raghvendra K Dubey
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Dna Synthesis ◽  
Angiogenesis Inhibitor ◽  
Inhibitory Effect ◽  
Cell Number ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Local Synthesis ◽  
The Right

P70 Methylation of 2-hydroxyestradiol(2OHE; endogenous estradiol metabolite) to 2-methoxyestradiol (2MeOE; angiogenesis inhibitor)by COMT plays a key role in mediating the anti-mitogenic effects of 2OHE on vascular smooth muscle cell (SMC)growth. Catecholamines such as norepinephrine (NE) are also substrates for COMT and increased levels of NE are associated with vasoocclusive disorders. We hypothesize that increased endogenous synthesis/levels of NE under pathophysiological conditions may abrogate the vasoprotective effects of 2OHE by competing for COMT and inhibiting 2MeOE formation. To test this hypothesis we investigated the anti-mitogenic effects of .001-10μM 2OHE on 2.5% FCS-induced SMC growth (cell number, DNA synthesis [thymidine incorporation], collagen synthesis [proline incorporatio])in rat and human aortic SMCs in the presence and absence of NE (0.1-40μM). NE concentration-dependently abrogated the inhibitory effects of 2OHE on SMC growth and in the presence of 10μM NE the inhibitory curve of 2OHE on SMC growth was shifted to the right(P<.05). In the presence of 10μM NE, the inhibitory effect of 1μM 2OHE on DNA synthesis was reduced from 70±3% to 24±2% (P<.05), and this effect of NE was mimicked by isoproterenol (ISO) and epinephrine (EPI). Additionally, NE (0.5-2.5mM) inhibited the metabolism of 10μM 2OHE to 2MeOE in a concentration-dependent manner and the effects of NE were mimicked by ISO, EPI, metanephrine, normetanephrine and 3,4-dihydroxymandelic acid. At 0.5 mM ISO, NE and EPI inhibited 2MeoE formation by 70±4%,20±2% and 40±2%, respectively. Our findings suggest that increases in local synthesis of catecholamines within the vasculature may abrogate the anti-vasoocclusive effects of estradiol and 2OHE by blocking 2MeOE formation. In conclusion, the interaction between catecholamines and 2OHE may play a key role in the biology of vascular SMC growth.

Effects of extracellular ATP on ICa, [Ca2+]i, and contraction in isolated ferret ventricular myocytes

1993 ◽  
Vol 264 (3) ◽  
pp. C702-C708 ◽  
Author(s):  
Y. Qu ◽  
H. M. Himmel ◽  
D. L. Campbell ◽  
H. C. Strauss
Keyword(s):  
Action Potential ◽  
Ventricular Myocytes ◽  
Ventricular Myocardium ◽  
Inhibitory Effect ◽  
Extracellular Atp ◽  
Maximal Effect ◽  
Dependent Manner ◽  
Patch Clamp Technique ◽  
Concentration Dependent Manner ◽  
The Right

The effects of extracellular ATP on the voltage-activated "L-type" Ca current (ICa), action potential, resting and transient intracellular Ca2+ levels, and cell contraction were examined in enzymatically isolated myocytes from the right ventricles of ferrets. With the use of the whole cell patch-clamp technique, extracellular ATP (10(-7) to 10(-3) M) inhibited ICa in a time- and concentration-dependent manner. ATP decreased the peak amplitude of ICa without altering the residual current at the end of 500-ms clamp steps. The concentration-response relationship for ATP inhibition of ICa was well described by a conventional Michaelis-Menten relationship with a half-maximal inhibitory concentration of 1 microM and a maximal effect of 50%. Consistent with its inhibitory effect on ICa, ATP hyperpolarized the plateau phase and shortened the action potential duration. In fura-2-loaded myocytes, extracellular ATP did not change the resting myoplasmic Ca2+ levels; however, when current was elicited under voltage-clamp conditions, ATP both decreased the myoplasmic intracellular Ca2+ transient and inhibited the degree of cell shortening. Our results suggest that ATP could be a genuine and potent extracellular modulator of cardiac function in ferret ventricular myocardium.

Cocaine Induces Apoptosis in Primary Cultured Rat Aortic Vascular Smooth Muscle Cells: Possible Relationship to Aortic Dissection, Atherosclerosis, and Hypertension

2004 ◽  
Vol 23 (4) ◽  
pp. 233-237 ◽  
Author(s):  
Jialin Su ◽  
Jianfeng Li ◽  
Wenyan Li ◽  
Bella T. Altura ◽  
Burton M. Altura
Keyword(s):  
Smooth Muscle ◽  
Aortic Dissection ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Cocaine Abuse ◽  
Cardiovascular Effects ◽  
Muscle Cells ◽  
Dependent Manner ◽  
Concentration Dependent Manner

Cocaine abuse is known to induce many adverse cardiovascular effects, including hypertension, atherosclerosis, and aortic dissection. A major physiological event leading to these pathophysiological actions of cocaine could be apoptosis. This study was designed to investigate if primary cultured rat aortic vascular smooth muscle cells (VSMCs) can undergo apoptosis when treated with cocaine. After treatment with cocaine (10−6 to 10−4 M), morphological analysis of aortic VSMCs using confocal fluoresence microscopy showed that the percentage of apoptotic aortic VSMCs increased after cocaine (10−6 to 10−4 M) treatment for 12, 24, and 48 h. These results demonstrate that aortic VSMCs can undergo rapid apoptosis in response to cocaine in a concentration-dependent manner. Cocaine-induced apoptosis may thus play a major role in cocaine abuse-induced aortic dissection, atherosclerosis, and hypertension.

scholarly journals Homocysteine promotes vascular smooth muscle cell migration by induction of the adipokine resistin

2009 ◽  
Vol 297 (6) ◽  
pp. C1466-C1476 ◽  
Author(s):  
Changtao Jiang ◽  
Heng Zhang ◽  
Weizhen Zhang ◽  
Wei Kong ◽  
Yi Zhu ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cell ◽  
Muscle Cell ◽  
Vascular Smooth Muscle Cell ◽  
Focal Adhesions ◽  
Diabetic Patients ◽  
Dependent Manner ◽  
Concentration Dependent Manner

Adipokines may represent a mechanism linking insulin resistance to cardiovascular disease. We showed previously that homocysteine (Hcy), an independent risk factor for cardiovascular disease, can induce the expression and secretion of resistin, a novel adipokine, in vivo and in vitro. Since vascular smooth muscle cell (VSMC) migration is a key event in vascular disease, we hypothesized that adipocyte-derived resistin is involved in Hcy-induced VSMC migration. To confirm our hypothesis, Sprague-Dawley rat aortic SMCs were cocultured with Hcy-stimulated primary rat epididymal adipocytes or treated directly with increasing concentrations of resistin for up to 24 h. Migration of VSMCs was investigated. Cytoskeletal structure and cytoskeleton-related proteins were also detected. The results showed that Hcy (300–500 μM) increased migration significantly in VSMCs cocultured with adipocytes but not in VSMC cultured alone. Resistin alone also significantly increased VSMC migration in a time- and concentration-dependent manner. Resistin small interfering RNA (siRNA) significantly attenuated VSMC migration in the coculture system, which indicated that adipocyte-derived resistin mediates Hcy-induced VSMC migration. On cell spreading assay, resistin induced the formation of focal adhesions near the plasma membrane, which suggests cytoskeletal rearrangement via an α5β1-integrin-focal adhesion kinase/paxillin-Ras-related C3 botulinum toxin substrate 1 (Rac1) pathway. Our data demonstrate that Hcy promotes VSMC migration through a paracrine or endocrine effect of adipocyte-derived resistin, which provides further evidence of the adipose-vascular interaction in metabolic disorders. The migratory action exerted by resistin on VSMCs may account in part for the increased incidence of restenosis in diabetic patients.

Darusentan is a potent inhibitor of endothelin signaling and function in both large and small arteriesThis article is one of a selection of papers published in the two-part special issue entitled 20 Years of Endothelin Research.

2010 ◽  
Vol 88 (8) ◽  
pp. 840-849 ◽  
Author(s):  
Faquan Liang ◽  
Christopher B. Glascock ◽  
Denise L. Schafer ◽  
Jennifer Sandoval ◽  
LouAnn Cable ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Potent Inhibitor ◽  
Inositol Phosphate ◽  
Contractile Activity ◽  
Binding Activity ◽  
Dependent Manner ◽  
Endothelin Receptor ◽  
Resistance Arteries ◽  
Concentration Dependent Manner

Endothelin is a potent vasoconstrictor often up-regulated in hypertension. Endothelin vasoconstriction is mediated via the G-protein coupled endothelin A (ETA) receptor present on vascular smooth muscle. Endothelin receptor antagonists (ERAs) have been shown to antagonize ET-induced vasoconstriction. We describe the primary pharmacology of darusentan, a propanoic acid based ERA currently in phase 3 clinical trials for resistant hypertension. Darusentan was tested in membrane-, cell-, and tissue-based assays to determine its biochemical and functional potency. Rat aortic vascular smooth muscle cells (RAVSMs) were characterized using flow cytometry. RAVSM membrane fractions tested in saturation experiments exhibited moderate endothelin receptor density. Receptor counting revealed that >95% of the endothelin receptors in these fractions were the ETA subtype. (S)-Darusentan competed for radiolabeled endothelin binding in RAVSM membranes with single-site kinetics, exhibiting a Ki = 13 nmol/L. (R)-Darusentan exhibited no binding activity. In cultured RAVSMs, endothelin induced increases in inositol phosphate and Ca2+ signaling, both of which were attenuated by (S)-darusentan in a concentration-dependent manner. In isolated endothelium-denuded rat aortic rings, (S)-darusentan inhibited endothelin-induced vascular contractility with a pA2 = 8.1 ± 0.14 (n = 4 animals; mean ± SD). (R)-Darusentan had no effect. The vasorelaxant potency of (S)-darusentan did not change when determined in isolated denuded rat mesenteric arterioles, suggesting a similar mode of action in both conductance and resistance arteries. In vascular smooth muscle, (S)-darusentan is an ERA with high affinity for the ET receptor, which in this preparation is predominantly ETA receptors. (S)-Darusentan inhibits endothelin-induced signaling related to pro-contractile activity and is a potent inhibitor of vasoconstriction in large and small arteries.

scholarly journals Effects of dexmedetomidine on porcine pulmonary artery vascular smooth muscle

2019 ◽  
Author(s):  
Mami Chikuda ◽  
Kenichi Sato
Keyword(s):  
Smooth Muscle ◽  
Pulmonary Artery ◽  
Vascular Smooth Muscle ◽  
Local Anesthetics ◽  
Pulmonary Arteries ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Duration Of Action ◽  
Porcine Pulmonary Artery ◽  
Ca2 Channels

Abstract Background Dexmedetomidine is added to local anesthetics to increase their potency and extend their duration of action, thus providing postoperative analgesia with a single administration. However, the effects and mechanism of action of dexmedetomidine on pulmonary arteries have not been determined. The aim of this study was to investigate the effect of dexmedetomidine on pulmonary artery vascular smooth muscle, evaluating changes in contraction tension. Methods Endothelium-denuded porcine pulmonary arteries were sliced into 2- to 3-mm rings. Changes in isometric contraction tension were measured with the addition of various substances at various concentrations, under different conditions of baseline stimulation (with KCl, Adrenaline, caffeine, or histamine) and different conditions of Ca2+ depletion with intracellular reservoirs or extracellular stores depleted. Results Dexmedetomidine increased the contraction tension induced by high-KCl depolarization in a concentration-dependent manner. Dexmedetomidine inhibited receptor-activated Ca2+ channels (RACCs) and phosphatidylinositol-1,4,5-triphosphate-induced Ca2+ release (IICR), but not Ca2+-induced Ca2+ release (CICR). Conclusions Dex increased the contraction tension resulting from depolarization stimulation by high KCl in a concentration-dependent manner in porcine pulmonary artery vascular smooth muscle. The enhancement of high KCl-induced contraction with Dex addition was mediated by α2 receptors. Dex suppressed increases in contraction tension induced by receptor stimulation with adrenaline, also in a concentration-dependent manner. Dex inhibited RACC and IICR, but not CICR. Elucidating the effects and mechanisms of action of Dex in the central arteries is likely to be useful as basic data for creating Dex-containing local anesthetics.

Ca2+- and Myosin Phosphorylation–independent Relaxation by Halothane in K+-depolarized Rat Mesenteric Arteries

2003 ◽  
Vol 99 (3) ◽  
pp. 656-666 ◽  
Author(s):  
Isao Tsuneyoshi ◽  
Dongya Zhang ◽  
Walter A. Boyle
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Mesenteric Arteries ◽  
Dependent Manner ◽  
Resistance Arteries ◽  
Concentration Dependent Manner ◽  
Myosin Phosphorylation ◽  
High K ◽  
Mlc Phosphorylation ◽  
Depolarized Smooth Muscle

Background Volatile anesthetics inhibit vascular smooth muscle contraction, but the mechanisms responsible are uncertain. In this study, the effects of halothane on Ca2+ signaling and Ca2+ activation of contractile proteins were examined in high K+-depolarized smooth muscle from rat mesenteric resistance arteries. Methods Vessels were cannulated and held at a constant transmural pressure (40 mmHg). Image analysis and microfluorimetry were used to simultaneously measure vessel diameter and smooth muscle intracellular [Ca2+] concentration ([Ca2+]i). Myosin light chain (MLC) phosphorylation was measured using the Western blotting technique. Results Step increases in extracellular [Ca2+] concentration (0-10 mM) in high K+ (40 mM)-depolarized smooth muscle produced incremental increases in [Ca2+]i, MLC phosphorylation, and contraction. Halothane (0.5-4.5%) inhibited contraction in a concentration-dependent manner, but the decrease in [Ca2+]i was small, and there was a marked shift in the [Ca2+]i-contraction relationship to the right, indicating an important Ca2+ desensitizing effect. Halothane (0.5-4.5%) did not affect MLC phosphorylation or the [Ca2+]-MLC phosphorylation relationship, but the MLC phosphorylation-contraction relationship was also shifted rightward, indicating an "MLC phosphorylation" desensitizing effect. In contrast, control relaxations produced by the Ca2+ channel blocker nifedipine were accompanied by decreases in both [Ca2+]i and MLC phosphorylation, and nifedipine had no affect on the [Ca2+]i-contraction, [Ca2+]i-MLC phosphorylation, and MLC phosphorylation-contraction relationships. Conclusions In high K+-depolarized vascular smooth muscle, halothane relaxation is largely mediated by a Ca2+ and MLC phosphorylation desensitizing effect. These results suggest that the relaxing action of halothane is independent of the classic Ca2+-induced myosin phosphorylation contraction mechanism.

Neuropeptide Y stimulates DNA synthesis in human vascular smooth muscle cells through neuropeptide Y Y1 receptors

2000 ◽  
Vol 78 (3) ◽  
pp. 256-259 ◽  
Author(s):  
T Nilsson ◽  
L Edvinsson
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Dna Synthesis ◽  
Neuropeptide Y ◽  
Vascular Smooth Muscle Cells ◽  
Thymidine Incorporation ◽  
Muscle Cells ◽  
Dependent Manner ◽  
Mitogenic Effect

We investigated the mitogenic effect, measured as [3H]thymidine incorporation, of neuropeptide Y (NPY) on smooth muscle cells (SMCs) from human subcutaneous arteries (diameter: 0.4 mm). NPY stimulated DNA synthesis in a concentration-dependent manner, Emax 32 ± 5% relative to control. The effect was potently antagonised by the NPY Y1 receptor antagonist BIBP3226 ((R)-N2-(diphenylacetyl)-N-[(4-hydroxy-phenyl)methyl]-D-arginine-amide), indicating the effect to be mediated via the NPY Y1 receptor. Noradrenaline (NA) also induced mitogenesis, Emax 35 ± 10% relative to control. When added together, NPY and NA potentiated the [3H]thymidine incorporation, Emax 109 ± 38% relative to control. Also, this effect seems to be mediated by the NPY Y1 receptor, since BIBP3226 blocked the effect (44 ± 9% relative to control). The mitogenic effect of NPY and NA, two important transmitters of the sympathetic nervous system, might have clinical consequences on conditions with elevated sympathetic nerve activity.Key words: BIBP3226, mitogenesis, neuropeptide Y, vascular smooth muscle cells.

High glucose abolishes the antiproliferative effect of 17β-estradiol in human vascular smooth muscle cells

2002 ◽  
Vol 282 (4) ◽  
pp. E746-E751 ◽  
Author(s):  
Shanhong Ling ◽  
Peter J. Little ◽  
Maro R. I. Williams ◽  
Aozhi Dai ◽  
Kazuhiko Hashimura ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Dna Synthesis ◽  
High Glucose ◽  
Antiproliferative Effect ◽  
Dependent Manner ◽  
Vsmc Proliferation ◽  
Normal Glucose ◽  
17Β Estradiol ◽  
Pkc Β

We examined effects of 17β-estradiol (E2) on human vascular smooth muscle cell (VSMC) proliferation under normal (5 mmol/l) and high (25 mmol/l) glucose concentrations. Platelet-derived growth factor (PDGF) BB (20 ng/ml)-induced increases in DNA synthesis and proliferation were greater in high than normal glucose concentrations; the difference in DNA synthesis was abolished by a protein kinase C (PKC)-β inhibitor, LY-379196 (30 nmol/l). Western blotting showed that PKC-β1 protein increased in cells exposed to high glucose, whereas PKC-α protein and total PKC activity remained unchanged, compared with normal glucose cultures. In normal glucose, E2 (1–100 nmol/l) inhibited PDGF-induced DNA synthesis by 18–37% and cell proliferation by 16–22% in a concentration-dependent manner. The effects of E2 were blocked by the estrogen receptor (ER) antagonist ICI-182780, indicating ER dependence. In high glucose, the inhibitory effect of E2on VSMC proliferation was abolished but was restored in the presence of the PKC-β inhibitor LY-379196. Thus high glucose enhances human VSMC proliferation and attenuates the antiproliferative effect of E2 in VSMC via activation of PKC-β.

Antisense oligodeoxynucleotides targeting PDGF-B mRNA inhibit cell proliferation during embryonic rat lung development

Development ◽  
1994 ◽  
Vol 120 (8) ◽  
pp. 2163-2173 ◽  
Author(s):  
P. Souza ◽  
L. Sedlackova ◽  
M. Kuliszewski ◽  
J. Wang ◽  
J. Liu ◽  
...  
Keyword(s):  
Dna Synthesis ◽  
Lung Development ◽  
Neutralizing Antibodies ◽  
Fetal Lung ◽  
Inhibitory Effect ◽  
Antisense Oligodeoxynucleotides ◽  
Dependent Manner ◽  
Rat Lung ◽  
Embryonic Lung ◽  
Concentration Dependent Manner

There is increasing evidence to suggest that platelet-derived growth factor (PDGF) or PDGF-like molecules play a role in fetal lung morphogenesis. Our previous studies demonstrated the presence of PDGF-AA and PDGF-BB homodimers in embryonic and fetal rat lung. To explore further the role for PDGF-BB in embryonic lung development, we conducted intervention studies using PDGF-B chain-specific antisense oligodeoxynucleotides in a simple embryonic rat lung explant system. Unmodified antisense PDGF-B oligodeoxynucleotides inhibited, in a concentration-dependent manner, DNA synthesis of embryonic lung. A maximal inhibition of 50% was observed. The inhibitory effect of antisense PDGF-B oligodeoxynucleotides on DNA synthesis was reversed by the addition of exogenous PDGF-BB but not PDGF-AA. Antisense treatment decreased PDGF-BB but not PDGF-AA protein content, as assessed by immunoblot analyses. Incubation of lung explants with PDGF-BB neutralizing antibodies also resulted in an inhibition of DNA synthesis. Morphometric analyses of antisense-treated cultures showed a significant reduction in lung size when compared to control cultures. The epithelial component of the embryonic lungs was specifically reduced, both in mass and DNA labelling index, by antisense treatment. The number of terminal buds of the lung explants was not significantly affected by antisense PDGF-B treatment. Scrambled PDGF-B oligodeoxynucleotides had no effect. These data suggest that PDGF-BB is involved in regulating growth, but not the degree of branching, of embryonic rat lung.

Direct Inhibitory Effect of Chlorpromazine on Smooth Muscle of the Porcine Pulmonary Artery

1996 ◽  
Vol 85 (3) ◽  
pp. 616-625. ◽  
Author(s):  
Chie Sakihara ◽  
Junji Nishimura ◽  
Sei Kobayashi ◽  
Shosuke Takahashi ◽  
Hideo Kanaide
Keyword(s):  
Smooth Muscle ◽  
Specific Binding ◽  
Front Surface ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Ligand Displacement ◽  
Direct Inhibitory Effect ◽  
Pulmonary Arterial ◽  
Adrenergic Blocking

Background Chlorpromazine has been widely used by anesthesiologists to take advantage of its anesthesia-potentiating and vasorelaxing actions. However, the mechanisms of vasorelaxation induced by chlorpromazine are still not fully understood. Methods Using front-surface fluorometry of fura-2 and porcine pulmonary arterial strips, we investigated the effects of chlorpromazine on the intracellular Ca2+ concentration ([Ca2+]i) and force of vascular smooth muscle. The affinities of chlorpromazine and other neuroleptics to vascular alpha(1)-adrenergic receptors were then determined by a radio-ligand binding study. Results Chlorpromazine (as much as 1 microM) inhibited both the elevation of [Ca2+]i and force in pulmonary arterial smooth muscle induced by 80 mM K+-depolarization and 1 microM norepinephrine in a concentration-dependent manner. The extent of inhibition by chlorpromazine in norepinephrine-induced contraction was much greater than that in 80 mM K+-induced contraction. In contrast, as much as 1 microM chlorpromazine had no effect on the increases in [Ca2+]i or force induced by U46619, a thromboxane A2 analogue. Chlorpromazine also had no effect on the intracellular Ca2+ release induced by U46619. In a radio-ligand displacement study, chlorpromazine, haloperidol, phentolamine, trifluoperazine, and imipramine inhibited the specific binding of [3H]prazosin to the porcine aortic membranes, in this order of potency. Conclusions Chlorpromazine induces vasorelaxation through an alpha-adrenergic blocking action as well as a calcium antagonistic action; the former action may, therefore, play a major role in chlorpromazine-induced vasorelaxation.

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