Attenuation of the serotonin-induced increase in intracellular calcium in rat aortic smooth muscle cells by sarpogrelate

2003 ◽  
Vol 81 (11) ◽  
pp. 1056-1063 ◽  
Author(s):  
Harjot K Saini ◽  
Sushil K Sharma ◽  
Peter Zahradka ◽  
Hideo Kumamoto ◽  
Nobuakira Takeda ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Dependent Manner ◽  
Aortic Smooth Muscle Cells ◽  
Aortic Smooth Muscle ◽  
Receptor Sites ◽  
Intracellular Ca

Although serotonin (5-HT) induced proliferation of vascular smooth muscle cells is considered to involve changes in intracellular Ca2+ ([Ca2+]i), the mechanism of Ca2+ mobilization by 5-HT is not well defined. In this study, we examined the effect of 5-HT on rat aortic smooth muscle cells (RASMCs) by Fura-2 microfluorometry for [Ca2+]i measurements. 5-HT was observed to increase the [Ca2+]i in a concentration- and time-dependent manner. This action of 5-HT was dependent upon the extracellular concentration of Ca2+ ([Ca2+]e) and was inhibited by both Ca2+ channel antagonists (verapamil and diltiazem) and inhibitors of sarcoplasmic reticular Ca2+ pumps (thapsigargin and cyclopia zonic acid). The 5-HT-induced increase in [Ca2+]i was blocked by sarpogrelate, a 5-HT2A-receptor antagonist, but not by different agents known to block other receptor sites. 5-HT-receptor antagonists such as ketanserin, cinanserin, and mianserin, unlike methysergide, were also found to inhibit the 5-HT-induced Ca2+ mobilization, but these agents were less effective in comparison to sarpogrelate. On the other hand, the increase in [Ca2+]i in RASMCs by ATP, angiotensin II, endothelin-1, or phorbol ester was not affected by sarpogrelate. These results indicate that Ca2+ mobilization in RASMCs by 5-HT is mediated through the activation of 5-HT2A receptors and support the view that the 5-HT-induced increase in [Ca2+]i involves both the extracellular and intracellular sources of Ca2+.Key words: sarpogrelate, serotonin, vascular smooth muscle cells, intracellular Ca2+.

scholarly journals Metabolism of inositol 1,4,5-trisphosphate in permeabilized rat aortic smooth-muscle cells. Dependence on calcium concentration

1987 ◽  
Vol 245 (1) ◽  
pp. 305-307 ◽  
Author(s):  
M F Rossier ◽  
A M Capponi ◽  
M B Vallotton
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Calcium Concentration ◽  
Muscle Cells ◽  
Aortic Smooth Muscle Cells ◽  
Aortic Smooth Muscle ◽  
Inositol 1,4,5 Trisphosphate

The metabolism of [3H]inositol 1,4,5-trisphosphate ([3H]Ins(1,4,5)P3) was studied in permeabilized rat aortic smooth-muscle cells. Addition of [3H]Ins(1,4,5)P3 to the leaky cells led to formation of several labelled metabolites. Amounts of [3H]inositol bisphosphate and [3H]inositol 1,3,4,5-tetrakisphosphate ([3H]InsP4) reached a maximum within 2 min of incubation, whereas production of [3H]inositol monophosphate and [3H]inositol 1,3,4-trisphosphate ([3H]Ins(1,3,4)P3) was delayed. Formation of InsP4 and Ins(1,3,4)P3 was Ca2+-sensitive in the physiological intracellular range (0.06-5 microM), showing a maximum at 1 microM-Ca2+. A correlation between the formation of InsP4 and that of Ins(1,3,4)P3 was observed, suggesting that the former is the precursor of the latter. These results suggest that, in vascular smooth-muscle cells, Ins(1,4,5)P3 is metabolized via two distinct pathways: (1) a dephosphorylation pathway, leading to formation of inositol bis- and mono-phosphate; and (2) a Ca2+-sensitive phosphorylation/dephosphorylation pathway, involving formation of InsP4 and leading to formation of Ins(1,3,4)P3.

Angiotensin II modulates frizzled-2 receptor expression in rat vascular smooth muscle cells

2005 ◽  
Vol 108 (6) ◽  
pp. 523-530 ◽  
Author(s):  
Giovanna CASTOLDI ◽  
Serena REDAELLI ◽  
Willy M. M. van de GREEF ◽  
Cira R. T. di GIOIA ◽  
Giuseppe BUSCA ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Angiotensin Ii ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Ang Ii ◽  
Aortic Smooth Muscle

Ang II (angiotensin II) has multiple effects on vascular smooth muscle cells through the modulation of different classes of genes. Using the mRNA differential-display method to investigate gene expression in rat aortic smooth muscle cells in culture in response to 3 h of Ang II stimulation, we observed that Ang II down-regulated the expression of a member of the family of transmembrane receptors for Wnt proteins that was identified as Fzd2 [Fzd (frizzled)-2 receptor]. Fzds are a class of highly conserved genes playing a fundamental role in the developmental processes. In vitro, time course experiments demonstrated that Ang II induced a significant increase (P<0.05) in Fzd2 expression after 30 min, whereas it caused a significant decrease (P<0.05) in Fzd2 expression at 3 h. A similar rapid up-regulation after Ang II stimulation for 30 min was evident for TGFβ1 (transforming growth factor β1; P<0.05). To investigate whether Ang II also modulated Fzd2 expression in vivo, exogenous Ang II was administered to Sprague–Dawley rats (200 ng·kg−1 of body weight·min−1; subcutaneously) for 1 and 4 weeks. Control rats received normal saline. After treatment, systolic blood pressure was significantly higher (P<0.01), whereas plasma renin activity was suppressed (P<0.01) in Ang II- compared with the saline-treated rats. Ang II administration for 1 week did not modify Fzd2 expression in aorta of Ang II-treated rats, whereas Ang II administration for 4 weeks increased Fzd2 mRNA expression (P<0.05) in the tunica media of the aorta, resulting in a positive immunostaining for fibronectin at this time point. In conclusion, our data demonstrate that Ang II modulates Fzd2 expression in aortic smooth muscle cells both in vitro and in vivo.

Interleukin 6 stimulates growth of vascular smooth muscle cells in a PDGF-dependent manner

1991 ◽  
Vol 260 (5) ◽  
pp. H1713-H1717 ◽  
Author(s):  
U. Ikeda ◽  
M. Ikeda ◽  
T. Oohara ◽  
A. Oguchi ◽  
T. Kamitani ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Interleukin 6 ◽  
Thymidine Incorporation ◽  
Tritiated Thymidine ◽  
Muscle Cells ◽  
Thymidine Uptake ◽  
Dependent Manner

We have investigated the effect of interleukin 6 (IL-6) on the growth of vascular smooth muscle cells (VSMC) isolated from rat aortas. Murine recombinant IL-6 significantly increased the number of VSMC and stimulated tritiated thymidine incorporation into VSMC in a dose-dependent manner. The IL-6-induced thymidine incorporation into VSMC was totally inhibited by the Ca2+ channel blocker verapamil; however, IL-6 showed no effects on the intracellular Ca2+ level ([Ca2+]i) in VSMC. Antibody against platelet-derived growth factor (PDGF) also totally inhibited the IL-6-induced thymidine uptake. PDGF caused a significant increase in the [Ca2+]i, which was totally inhibited by verapamil. IL-6 mRNA was not detected in unstimulated “quiescent” VSMC, but its expression was stimulated by exposure of VSMC to 10% fetal bovine serum. Immunohistochemical study using anti-PDGF antibody showed that IL-6 stimulated PDGF production in VSMC. These results support the premise that IL-6 is released by VSMC in an autocrine manner and promotes the growth of VSMC via induction of endogenous PDGF production.

Ets-1 is an early response gene activated by ET-1 and PDGF-BB in vascular smooth muscle cells

1998 ◽  
Vol 274 (2) ◽  
pp. C472-C480 ◽  
Author(s):  
Shinji Naito ◽  
Shunichi Shimizu ◽  
Shigeto Maeda ◽  
Jianwei Wang ◽  
Richard Paul ◽  
...  
Keyword(s):  
Gene Expression ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Inositol Phosphate ◽  
Muscle Cells ◽  
Tetraacetic Acid ◽  
Acetoxymethyl Ester ◽  
Intracellular Ca

Ets-1 is a transcription factor that activates expression of matrix-degrading proteinases such as collagenase and stromelysin. To study the control of ets-1 gene expression in rat vascular smooth muscle cells (VSMC), cells were exposed to factors known to regulate VSMC migration and proliferation. Platelet-derived growth factor-BB (PDGF-BB), endothelin-1 (ET-1), and phorbol 12-myristate 13-acetate (PMA) induced a dose-dependent expression of ets-1 mRNA. These effects were abrogated by inhibition of protein kinase C (PKC) by H-7 or chronic PMA treatment. Ets-1 mRNA was superinduced by PDGF-BB and ET-1 in the presence of cycloheximide. The chelation of intracellular Ca2+ by 1,2-bis(2-aminophenoxy)ethane- N, N, N′, N′-tetraacetic acid-acetoxymethyl ester and the depletion of endoplasmic reticulum intracellular Ca2+concentration ([Ca2+]i) by thapsigargin inhibited PDGF-BB- and ET-1-induced ets-1 mRNA, whereas ethylene glycol-bis(β-aminoethyl ether)- N, N, N′, N′-tetraacetic acid had no effect. However, [Ca2+]irelease alone was not sufficient to increase ets-1 mRNA. Forskolin blocked ET-1-, PDGF-BB-, and PMA-induced ets-1 mRNA, as well as inositol phosphate formation, consistent with an effect through impairment of PKC activation. Inhibitors of ets-1 gene expression, such as H-7 and herbimycin A, inhibited the ET-1 induction of collagenase I mRNA. We propose that ets-1 may be an important element in the orchestration of matrix proteinase expression and of vascular remodeling after arterial injury.

ANG II increases TIMP-1 expression in rat aortic smooth muscle cells in vivo

2003 ◽  
Vol 284 (2) ◽  
pp. H635-H643 ◽  
Author(s):  
Giovanna Castoldi ◽  
Cira R. T. di Gioia ◽  
Federico Pieruzzi ◽  
Cristina D'Orlando ◽  
Willy M. M. van de Greef ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Vascular Wall ◽  
Dependent Manner ◽  
Ang Ii ◽  
Maximal Increase ◽  
Aortic Smooth Muscle Cells ◽  
Aortic Smooth Muscle

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) are involved in tissue remodeling processes. TIMP-1 is the main native inhibitor of MMPs and it contributes to the development of tissue fibrosis. It is known that ANG II plays a fundamental role in vascular remodeling. In this study, we investigated whether ANG II modulates TIMP-1 expression in rat aortic smooth muscle cells. In vitro, ANG II induces TIMP-1 mRNA expression in a dose-dependent manner. The maximal increase in TIMP-1 expression was present after 3 h of ANG II stimulation. The ANG II increase in TIMP-1 expression was mediated by the ANG type 1 receptors because it was blocked by losartan. The increase in TIMP-1 expression was present after the first ANG II treatment, whereas repeated treatments (3 and 5 times) did not modify TIMP-1 expression. In vivo, exogenous ANG II was administered to Sprague-Dawley rats (200 ng · kg−1· min−1sc) for 6 and 25 days. Control rats received physiological saline. After treatment, systolic blood pressure was significantly higher ( P < 0.01), whereas plasma renin activity was suppressed ( P < 0.01), in ANG II-treated rats. ANG II increased TIMP-1 expression in the aorta of ANG II-treated rats both at the mRNA ( P < 0.05) and protein levels as evaluated by Western blotting ( P < 0.05) and/or immunohistochemistry. Neither histological modifications at the vascular wall nor differences in collagen content in the tunica media were present in both the ANG II- and saline-treated groups. Our data demonstrate that ANG II increases TIMP-1 expression in rat aortic smooth muscle cells. In vivo, both short- and long-term chronic ANG II treatments increase TIMP-1 expression in the rat aorta. TIMP-1 induction by ANG II in aortic smooth muscle cells occurs in the absence of histological changes at the vascular wall.

Characterization of ANF receptors in cultured renal cortical vascular smooth muscle cells

1991 ◽  
Vol 260 (3) ◽  
pp. C424-C432 ◽  
Author(s):  
M. L. Bea ◽  
J. C. Dussaule ◽  
M. Bens ◽  
R. Ardaillou
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
High Performance ◽  
Specific Binding ◽  
Muscle Cells ◽  
Threshold Concentration ◽  
Receptor Sites

Because atrial natriuretic factor (ANF) has been demonstrated to decrease resistances in cortical renal vessels in vivo, we studied 125I-ANF binding and ANF-dependent guanosine 3',5'-cyclic monophosphate (cGMP) production in subcultured vascular smooth muscle cells (VSMC) prepared from the rabbit renal cortex. 125I-ANF specific binding at 4 degrees C represented 70% of total binding and reached a plateau at 30-60 min. Equilibrium saturation binding curves suggested one group of high-affinity receptor sites (KD = 78 +/- 16 pM, Bmax = 45 +/- 11 fmol/mg) but were compatible with several groups exhibiting close binding parameters. ANF, [Ala7,Ala23]ANF (a linear analogue), and C-ANF-(4-23) (a ligand of C receptors) inhibited 125I-ANF binding at 37 degrees C with nearly similar potencies. In contrast, at 4 degrees C, complete or nearly complete inhibition of binding was obtained with ANF and linear ANF, the latter exhibiting the weakest potency, whereas C-ANF-(4-23) displaced only 35% of the tracer. ANF markedly stimulated cGMP accumulation, with a threshold concentration of 10 pM and a stimulation of 115 times basal value at 0.1 microM. Linear ANF was also stimulatory with a much weaker potency. Around 25% of 125I-ANF bound to cell surface was internalized at 37 degrees C. Phenylarsine oxide partially inhibited internalization as well as the inhibitory potency of C-ANF-(4-23) on 125I-ANF binding. As shown by high-performance liquid chromatography extracellular 125I-ANF was rapidly degraded at 37 degrees C into its 125I-COOH-terminal tripeptide and 125I-Tyr.(ABSTRACT TRUNCATED AT 250 WORDS)

Hypoxia-induced expression of VEGF is reversible in myocardial vascular smooth muscle cells

1997 ◽  
Vol 273 (2) ◽  
pp. H628-H633 ◽  
Author(s):  
J. W. Gu ◽  
T. H. Adair
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Conditioned Media ◽  
Dependent Manner ◽  
Induced Expression ◽  
Protein Levels

We determined whether hypoxia-induced expression of vascular endothelial growth factor (VEGF) can be reversed by a normoxic environment. Dog myocardial vascular smooth muscle cells (MVSMCs) were exposed to hypoxia (1% O2) for 24 h and then returned to normoxia (20% O2). VEGF protein levels increased by more than fivefold after 24 h of hypoxia and returned to baseline within 24 h of the return of the cells to normoxia. Northern blot analysis showed that hypoxia caused a 5.5-fold increase in VEGF mRNA, and, again, the expression was reversed after reinstitution of normoxia. Additional measurements showed that basic fibroblast growth factor and platelet-derived growth factor protein levels were not induced by hypoxia and that hypoxia caused a fourfold decrease in transforming growth factor-beta 1 protein levels. Hypoxia conditioned media from MVSMCs caused human umbilical vein endothelial cells to increase [3H]thymidine incorporation by twofold, an effect that was blocked in a dose-dependent manner by anti-human VEGF antibody. The hypoxia conditioned media had no effect on MVSMC proliferation. These findings suggest that VEGF expression can be bidirectionally controlled by tissue oxygenation, and thus support the hypothesis that VEGF is a physiological regulator of angiogenesis.

Differential blockade of agonist- and depolarization-induced 45Ca2+ influx in smooth muscle cells

1989 ◽  
Vol 257 (4) ◽  
pp. C607-C611 ◽  
Author(s):  
A. Wallnofer ◽  
C. Cauvin ◽  
T. W. Lategan ◽  
U. T. Ruegg
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Aortic Smooth Muscle Cells ◽  
Aortic Smooth Muscle ◽  
Gamma S ◽  
Ca2 Channels ◽  
Stimulation Of

ATP stimulated 45Ca2+ influx in rat aortic smooth muscle cells in a concentration-dependent manner (EC50 = 3.6 +/- 0.5 X 10(-7) M). ADP and GTP were less effective than ATP in stimulating 45Ca2+ influx; AMP was weakly active and the adenosine agonist 5'-(N-ethyl-carboxamido)-adenosine (NECA) had no effect. ATP gamma S was about equieffective with ATP, whereas alpha,beta-methylene-ATP (APCPP) did not induce 45Ca2+ influx. Stimulation of 45Ca2+ influx by ATP was not abolished by the dihydropyridine Ca2+ channel antagonist darodipine (PY 108-068), which completely blocked depolarization-induced 45Ca2+ influx. Inorganic cations (La3+, Cd2+, Co2+, Ni2+, Mn2+, and Mg2+) were able to inhibit both agonist- and depolarization-induced 45Ca2+ influx. Cd2+, however, was approximately 20 times more selective in blocking K+-stimulated than agonist-stimulated 45Ca2+ influx. These data indicate that ATP-stimulated Ca2+ influx in rat aortic smooth muscle cells is resistant to darodipine but is reduced by La3+, Cd2+, and other inorganic blockers of Ca2+ channels.

Mechanism of angiotensin II-induced arachidonic acid metabolite release in aortic smooth muscle cells: involvement of phospholipase D

1997 ◽  
Vol 136 (2) ◽  
pp. 207-212 ◽  
Author(s):  
Junji Shinoda ◽  
Osamu Kozawa ◽  
Atsushi Suzuki ◽  
Yasuko Watanabe-Tomita ◽  
Yutaka Oiso ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Smooth Muscle ◽  
Angiotensin Ii ◽  
Smooth Muscle Cells ◽  
Phospholipase D ◽  
Muscle Cells ◽  
Dependent Manner ◽  
Ang Ii ◽  
Aortic Smooth Muscle Cells ◽  
Aortic Smooth Muscle

Abstract In a previous study, we have shown that angiotensin II (Ang II) activates phosphatidylcholinehydrolyzing phospholipase D due to Ang II-induced Ca2+ influx from extracellular space in subcultured rat aortic smooth muscle cells. In the present study, we have investigated the role of phospholipase D in Ang II-induced arachidonic acid (AA) metabolite release and prostacyclin synthesis in subcultured rat aortic smooth muscle cells. Ang II significantly stimulated AA metabolite release in a concentration-dependent manner in the range between 1 nmol/l and 0·1 μmol/l. d,l-Propranolol hydrochloride (propranolol), an inhibitor of phosphatidic acid phosphohydrolase, significantly inhibited the Ang II-induced release of AA metabolites. The Ang II-induced AA metabolite release was reduced by chelating extracellular Ca2+ with EGTA. Genistein, an inhibitor of protein tyrosine kinases, significantly suppressed the Ang II-induced AA metabolite release. 1,6-Bis-(cyclohexyloximinocarbonylamino)-hexane (RHC-80267), a potent and selective inhibitor of diacylglycerol lipase, significantly inhibited the Ang II-induced AA metabolite release. Both propranolol and RHC-80267 inhibited the Ang II-induced synthesis of 6-keto-prostaglandin F1α, a stable metabolite of prostacyclin. The synthesis was suppressed by genistein. These results strongly suggest that the AA metabolite release induced by Ang II is mediated, at least in part, through phosphatidylcholine hydrolysis by phospholipase D activation in aortic smooth muscle cells. European Journal of Endocrinology 136 207–212

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