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John L, Ko NL, Gokin A, Gokina N, Mandalà M, Osol G. The Piezo1 cation channel mediates uterine artery shear stress mechanotransduction and vasodilation during rat pregnancy. Am J Physiol Heart Circ Physiol 2018; 315:H1019-H1026. [PMID: 30004235 DOI: 10.1152/ajpheart.00103.2018] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
During mammalian pregnancy, the uterine circulation must undergo substantial vasodilation and growth to maintain sufficient uteroplacental perfusion. Although we and others have shown that nitric oxide (NO) is a key mediator of these processes, the mechanisms that augment uterine artery NO signaling during gestation have not been identified. We hypothesized that Piezo1, a recently discovered cation channel, may be involved in the process of shear stress mechanotransduction, as other studies have shown that it is both mechanosensitive and linked to NO production. Surprisingly, there are no studies on Piezo1 in the uterine circulation. Our aims in the present study were to determine whether this novel channel is 1) present in uterine arteries, 2) regulated by gestation, 3) functionally relevant (able to elicit rises in intracellular Ca2+ concentration and vasodilation), and 4) linked to NO. Immunohistochemistry confirmed that Piezo1 is present in uterine arteries, primarily but not exclusively in endothelial cells. Western blot analysis showed that its protein expression was elevated during gestation. In pressurized main uterine arteries, pharmacological activation of Piezo1 by Yoda1 produced near maximal vasodilation and was associated with significant increases in intracellular Ca2+ concentration in endothelial cell sheets. Shear stress induced by intraluminal flow produced reversible vasodilations that were inhibited >50% by GsMTx-4, a Piezo1 inhibitor, and by Nω-nitro-l-arginine methyl ester/ Nω-nitro-l-arginine, inhibitors of NO synthase. These findings are the first to implicate a functional role for Piezo1 in the uterine circulation as a mechanosensor of endothelial shear stress. Moreover, our data demonstrate that Piezo1 activation leads to vasodilation via NO and indicate that its molecular expression is upregulated during pregnancy. NEW & NOTEWORTHY This is the first study to highlight Piezo1 in the uterine circulation. As a potentially important endothelial mechanosensor of shear stress, Piezo1 may be linked to mechanisms that support increased uteroplacental perfusion during pregnancy. Listen to this article's corresponding podcast at https://ajpheart.podbean.com/e/piezo1-mechanotransduction-in-the-uterine-circulation/ .
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Affiliation(s)
- Liam John
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Larner College of Medicine, University of Vermont , Burlington, Vermont
| | - Nga Ling Ko
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Larner College of Medicine, University of Vermont , Burlington, Vermont
| | - Alexander Gokin
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Larner College of Medicine, University of Vermont , Burlington, Vermont
| | - Natalia Gokina
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Larner College of Medicine, University of Vermont , Burlington, Vermont
| | - Maurizio Mandalà
- Department of Biology, Ecology and Earth Science, University of Calabria , Cosenza , Italy
| | - George Osol
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Larner College of Medicine, University of Vermont , Burlington, Vermont
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Maille N, Gokina N, Mandalà M, Colton I, Osol G. Mechanism of hydralazine-induced relaxation in resistance arteries during pregnancy. Vascul Pharmacol 2016. [DOI: 10.1016/j.vph.2015.07.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Gokina N, Bonev A, Gokin A, Goloman G, Oppenheimer K. TRPV4 Channels Regulate Endothelial Ca Signaling in Rat Maternal Uteroplacental Vasculature. FASEB J 2015. [DOI: 10.1096/fasebj.29.1_supplement.794.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Natalia Gokina
- Department of ObstetricsGynecology and Reproductive Sciences University of VermontBurlingtonVermontUnited States
| | - Adrian Bonev
- Department of PharmacologyUniversity of VermontBurlingtonVermontUnited States
| | - Alexander Gokin
- Department of ObstetricsGynecology and Reproductive Sciences University of VermontBurlingtonVermontUnited States
| | - Gabriela Goloman
- Department of ObstetricsGynecology and Reproductive Sciences University of VermontBurlingtonVermontUnited States
| | - Karen Oppenheimer
- Department of ObstetricsGynecology and Reproductive Sciences University of VermontBurlingtonVermontUnited States
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Cipolla MJ, Chan SL, Sweet J, Tavares MJ, Gokina N, Brayden JE. Postischemic reperfusion causes smooth muscle calcium sensitization and vasoconstriction of parenchymal arterioles. Stroke 2014; 45:2425-30. [PMID: 24968928 DOI: 10.1161/strokeaha.114.005888] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
BACKGROUND AND PURPOSE Parenchymal arterioles (PAs) are high-resistance vessels in the brain that connect pial vessels to the microcirculation. We previously showed that PAs have increased vasoconstriction after ischemia and reperfusion that could increase perfusion deficit. Here, we investigated underlying mechanisms by which early postischemic reperfusion causes increased vasoconstriction of PAs. METHODS Isolated and pressurized PAs from within the middle cerebral artery territory were studied in male Wistar rats that were either nonischemic control (n=34) or after exposure to transient middle cerebral artery occlusion (MCAO) by filament occlusion for 2 hours with 30 minutes of reperfusion (MCAO; n=38). The relationships among pressure-induced tone, smooth muscle calcium (using Fura 2), and membrane potential were determined. Sensitivity of the contractile apparatus to calcium was measured in permeabilized arterioles using Staphylococcus aureus α-toxin. Reactivity to inhibition of transient receptor potential melastanin receptor type 4 (9-phenanthrol), Rho kinase (Y27632), and protein kinase C (Gö6976) was also measured. RESULTS After MCAO, PAs had increased myogenic tone compared with controls (47±2% versus 35±2% at 40 mm Hg; P<0.01), without an increase in smooth muscle calcium (177±21 versus 201±16 nmol/L; P>0.05) or membrane depolarization (-38±4 versus -36±1 mV; P>0.05). In α-toxin-permeabilized vessels, MCAO caused increased sensitivity of the contractile apparatus to calcium. MCAO did not affect dilation to transient receptor potential melastanin receptor type 4 or protein kinase C inhibition but diminished dilation to Rho kinase inhibition. CONCLUSIONS The increased vasoconstriction of PAs during early postischemic reperfusion seems to be due to calcium sensitization of smooth muscle and could contribute to infarct expansion and limit neuroprotective agents from reaching their target tissue.
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Affiliation(s)
- Marilyn J Cipolla
- From the Department of Neurological Sciences (M.J.C., S.-L.C., J.S.), Department of Pharmacology (M.J.C., M.J.T., J.E.B.), and Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Vermont, Burlington (M.J.C., N.G.).
| | - Siu-Lung Chan
- From the Department of Neurological Sciences (M.J.C., S.-L.C., J.S.), Department of Pharmacology (M.J.C., M.J.T., J.E.B.), and Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Vermont, Burlington (M.J.C., N.G.)
| | - Julie Sweet
- From the Department of Neurological Sciences (M.J.C., S.-L.C., J.S.), Department of Pharmacology (M.J.C., M.J.T., J.E.B.), and Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Vermont, Burlington (M.J.C., N.G.)
| | - Matthew J Tavares
- From the Department of Neurological Sciences (M.J.C., S.-L.C., J.S.), Department of Pharmacology (M.J.C., M.J.T., J.E.B.), and Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Vermont, Burlington (M.J.C., N.G.)
| | - Natalia Gokina
- From the Department of Neurological Sciences (M.J.C., S.-L.C., J.S.), Department of Pharmacology (M.J.C., M.J.T., J.E.B.), and Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Vermont, Burlington (M.J.C., N.G.)
| | - Joseph E Brayden
- From the Department of Neurological Sciences (M.J.C., S.-L.C., J.S.), Department of Pharmacology (M.J.C., M.J.T., J.E.B.), and Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Vermont, Burlington (M.J.C., N.G.)
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Cipolla MJ, Sweet J, Chan SL, Tavares MJ, Gokina N, Brayden JE. Increased pressure-induced tone in rat parenchymal arterioles vs. middle cerebral arteries: role of ion channels and calcium sensitivity. J Appl Physiol (1985) 2014; 117:53-9. [PMID: 24790017 DOI: 10.1152/japplphysiol.00253.2014] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Brain parenchymal arterioles (PAs) are high-resistance vessels that branch off pial arteries and perfuse the brain parenchyma. PAs are the target of cerebral small vessel disease and have been shown to have greater pressure-induced tone at lower pressures than pial arteries. We investigated mechanisms by which brain PAs have increased myogenic tone compared with middle cerebral arteries (MCAs), focusing on differences in vascular smooth muscle (VSM) calcium and ion channel function. The amount of myogenic tone and VSM calcium was measured using Fura 2 in isolated and pressurized PAs and MCAs. Increases in intraluminal pressure caused larger increases in tone and cytosolic calcium in PAs compared with MCAs. At 50 mmHg, myogenic tone was 37 ± 5% for PAs vs. 6.5 ± 4% for MCAs (P < 0.01), and VSM calcium was 200 ± 20 nmol/l in PAs vs. 104 ± 15 nmol/l in MCAs (P < 0.01). In vessels permeabilized with Staphylococcus aureus α-toxin, PAs were not more sensitive to calcium, suggesting calcium sensitization was not at the level of the contractile apparatus. PAs were 30-fold more sensitive to the voltage-dependent calcium channel (VDCC) inhibitor nifedipine than MCAs (EC50 for PAs was 3.5 ± 0.4 vs. 82.1 ± 2.1 nmol/l for MCAs;P < 0.01); however, electrophysiological properties of the VDCC were not different in VSM. PAs had little to no response to the calcium-activated potassium channel inhibitor iberiotoxin, whereas MCAs constricted ∼15%. Thus increased myogenic tone in PAs appears related to differences in ion channel activity that promotes VSM membrane depolarization but not to a direct sensitization of the contractile apparatus to calcium.
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Affiliation(s)
- Marilyn J Cipolla
- Department of Neurological Sciences, University of Vermont, Burlington, Vermont; Department of Pharmacology, University of Vermont, Burlington, Vermont; and Department of Obstetrics, Gynecology & Reproductive Sciences, University of Vermont, Burlington, Vermont
| | - Julie Sweet
- Department of Neurological Sciences, University of Vermont, Burlington, Vermont
| | - Siu-Lung Chan
- Department of Neurological Sciences, University of Vermont, Burlington, Vermont
| | - Matthew J Tavares
- Department of Pharmacology, University of Vermont, Burlington, Vermont; and
| | - Natalia Gokina
- Department of Obstetrics, Gynecology & Reproductive Sciences, University of Vermont, Burlington, Vermont
| | - Joseph E Brayden
- Department of Pharmacology, University of Vermont, Burlington, Vermont; and
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Mandalà M, Gokina N, Barron C, Osol G. Endothelial-derived hyperpolarization factor (EDHF) contributes to PlGF-induced dilation of mesenteric resistance arteries from pregnant rats. J Vasc Res 2011; 49:43-9. [PMID: 21985802 DOI: 10.1159/000329821] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Accepted: 05/28/2011] [Indexed: 01/13/2023] Open
Abstract
The aim of this study was to investigate the cellular mechanism involved in the potent vasodilatory action of PlGF on mesenteric resistance arteries from pregnant rats. PlGF (3 nM) induced a vasodilation of 64 ± 3.8% that was completely abolished by endothelial denudation. Significant dilation (28 ± 4.0%) remained, however, in the presence of nitric oxide synthase and cyclooxygenase inhibition, and was associated with significant reductions in vascular smooth muscle cell calcium. Absence of dilation in potassium-depolarizing solution (30 mM) confirmed its dependence on endothelial-derived hyperpolarization factor. Subsequent studies established that vasodilation was abolished by pharmacologic inhibition of SK(Ca) (apamin) and BK(Ca) (iberiotoxin) but not IK(Ca) (tram-34) potassium channels. In summary, PlGF acts through the release of a combination of endothelium-derived relaxation factors. Based on the results of potassium channel blockade, we suggest that it induces endothelial hyperpolarization via SK(Ca) channel activation; this, in turn, leads to the release of a diffusible mediator that activates vascular smooth muscle BK(Ca) channels, hyperpolarization and vasodilation. This is the first study to identify the mechanism for PlGF/VEGFR-1 resistance artery dilation in the pregnant state, whose attenuation likely contributes to the systemic hypertension characteristic of pre- eclampsia.
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Affiliation(s)
- Maurizio Mandalà
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of Vermont, College of Medicine, Burlington, Vt. 05405, USA. maurizio.mandala @ uvm.edu
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Fuller R, Colton I, Gokina N, Mandala M, Osol G. Local versus systemic influences on uterine vascular reactivity during pregnancy in the single-horn gravid rat. Reprod Sci 2011; 18:723-9. [PMID: 21285448 DOI: 10.1177/1933719110396700] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
This study was conducted to determine whether gestational changes in maternal uterine artery reactivity are primarily driven by local vs. systemic factors. Rats underwent surgical ligation of one oviduct, thereby restricting implantation and pregnancy to one uterine horn while maintaining a gestational endocrine milieu. Uterine arcuate arteries were isolated and cannulated to evaluate reactivity. Vessels from the implanted horn were significantly more sensitive to phenylephrine and less sensitive to sodium nitroprusside than those from the non-implanted horn; endothelial basal calcium levels were only increased in the implanted horn. Conversely, there were no differences in sensitivity to acetylcholine, or its effects on endothelial cell calcium, although efficacy was greater in vessels from the implanted vs. non-implanted horn. These findings demonstrate that local factors are predominant in inducing changes in vascular smooth muscle function, while endothelial adaptations result from an interplay between local and systemic factors, with distinct effects attributable to each.
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Affiliation(s)
- Robert Fuller
- Department of Obstetrics and Gynecology and Reproductive Sciences, University of Vermont College of Medicine, Burlington, VT 05405, USA
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Osol G, Barron C, Gokina N, Mandala M. Inhibition of nitric oxide synthases abrogates pregnancy-induced uterine vascular expansive remodeling. J Vasc Res 2009; 46:478-86. [PMID: 19204405 DOI: 10.1159/000200963] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2008] [Accepted: 10/18/2008] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS It was the aim of this study to test the hypothesis that hypertension and/or inhibition of nitric oxide (NO) synthases alters uterine vascular remodeling during pregnancy. METHODS Using a model of hypertension (NO synthase inhibition with L-NAME) in nonpregnant and pregnant rats, comparisons were made with age-matched controls, as well as with animals receiving hydralazine along with L-NAME to maintain normotension in the presence of NO synthase inhibition. Circumferential and axial remodeling of large (main uterine, MUA) and small (premyometrial radial) arteries were quantified and compared. RESULTS L-NAME treatment prevented expansive circumferential remodeling of the MUA; cotreatment with hydralazine was without effect. Circumferential remodeling of smaller premyometrial radial arteries was also significantly attenuated in hypertensive pregnant animals, while premyometrial radial arteries from rats receiving hydralazine with L-NAME were of intermediate diameter. Neither hypertension nor NO synthase inhibition had any effect on the substantial (200-300%) axial growth of MUA or premyometrial radial arteries. CONCLUSION NO plays a major role in facilitating pregnancy-induced expansive remodeling in the uterine circulation, particularly in larger arteries. Some beneficial effects of hydralazine on expansive circumferential remodeling were noted in smaller radial vessels, and these may be linked to its prevention of systemic hypertension and/or to local effects on the arterial wall. Neither NO synthase inhibition nor hypertension had any effect on arterial longitudinal growth.
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Affiliation(s)
- George Osol
- Department of Obstetrics and Gynecology, College of Medicine, University of Vermont, Burlington, Vt. 05405, USA.
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Fuller R, Barron C, Mandala M, Gokina N, Osol G. Predominance of local over systemic factors in uterine arterial remodeling during pregnancy. Reprod Sci 2009; 16:489-500. [PMID: 19164479 DOI: 10.1177/1933719108329816] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study used a rat model in which pregnancy was surgically restricted to one uterine horn to differentiate between local (fetoplacental) and systemic (endocrine) influences on uterine vascular remodeling during pregnancy. Sprague-Dawley rats with single-horn pregnancies were studied on day 20/22 of gestation and compared to age-matched nonpregnant and late-pregnant controls. The morphology (axial length, lumen diameter, wall thickness) of the main uterine artery and of smaller arcuate vessels showed that vascular growth was dramatically increased in the pregnant versus nonpregnant horn, (P < .05). Arcuate artery wall thickness increased in the nonpregnant horn (compared to nonpregnant controls, P < .05), suggesting a limited role for systemic hormonal influences on vascular remodeling. Notably, animals with only one functional horn compensated by increasing the average number of implantation sites per horn from 7.6 to 12.9, thereby maintaining essentially normal litter size without any reduction in fetal or placental weights. These results demonstrate unequivocally that local rather than systemic influences play the dominant role in uterine vascular gestational remodeling of both large and small uterine arteries, and reveal a significant adaptive process that maintains relatively normal fecundity in spite of surgical restriction of normal bilateral pregnancy.
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Affiliation(s)
- Robert Fuller
- Department of Ob/Gyn and Reproductive Sciences, University of Vermont College of Medicine, Burlington, Vermont 05405, USA
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Osol G, Celia G, Gokina N, Barron C, Chien E, Mandala M, Luksha L, Kublickiene K. Placental growth factor is a potent vasodilator of rat and human resistance arteries. Am J Physiol Heart Circ Physiol 2008; 294:H1381-7. [PMID: 18192215 DOI: 10.1152/ajpheart.00922.2007] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The objectives of this study were to determine whether placental growth factor (PlGF) exerts a vasodilatory effect on rat uterine vessels (arcuate arteries and veins) and to examine regional differences in reactivity by comparing these responses to those of comparably sized mesenteric vessels. We also sought to examine and compare its effects on human uterine and subcutaneous vessels. All vessels were studied in vitro, under pressurized (rat) or isometric wire-mounted (human) conditions, and exposed to a range of PlGF concentrations. Inhibitors of nitric oxide and prostaglandin synthesis were included in an effort to understand the causal mechanism(s). In rat uterine arteries, the effects of receptor inhibition and activation using selective ligands for VEGFR-1 (PlGF) vs. VEGFR-2 (VEGF-E) were determined, and real-time RT-PCR was performed to evaluate the effect of pregnancy on relative abundance of VEGFR-1 and VEGFR-2 message in the vascular wall. PlGF was a potent vasodilator of all vessels studied, with greatest sensitivity observed in rat uterine arteries. Pregnancy significantly augmented dilator sensitivity to PlGF, and this effect was associated with selective upregulation of VEGFR-1 message in the pregnant state. The contribution of nitric oxide was appreciable in rat and human uterine arteries, with lesser effects in rat uterine veins and mesenteric arteries, and with no observable effect in human subcutaneous vessels. Based on these results, we conclude that PlGF is a potent vasodilator of several vessel types in both humans and rats. Its potency and mechanism vary with physiological state and vessel location and are mediated solely by the VEGFR-1 receptor subtype. Gestational changes in the uterine circulation suggest that this factor may play a role in modulating uterine vascular remodeling and blood flow during the pregnant state.
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Affiliation(s)
- George Osol
- Department of Obstetrics and Gynecology, University of Vermont College of Medicine, Burlington, VT 05405, USA.
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Lu Y, Zhang H, Gokina N, Mandala M, Sato O, Ikebe M, Osol G, Fisher SA. Uterine artery myosin phosphatase isoform switching and increased sensitivity to SNP in a rat L-NAME model of hypertension of pregnancy. Am J Physiol Cell Physiol 2007; 294:C564-71. [PMID: 18094148 DOI: 10.1152/ajpcell.00285.2007] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Dramatic and vascular bed-specific hemodynamic changes occur in pregnancy and hypertension of pregnancy (HtP). Because myosin phosphatase (MP) is the primary effector of smooth muscle relaxation and a key target of signaling pathways that regulate vascular tone, we hypothesized that MP expression would be altered in these conditions. The abundance of the targeting/regulatory subunit of MP (MYPT1) mRNA and protein was increased 1.7- to 2.0-fold specifically in the uterine arteries (UAs) of late-pregnant rats without isoform switching. In a model of HtP in which nitric oxide (NO) synthesis is blocked by the chronic administration of N(omega)-nitro-L-arginine methyl ester, MYPT1 was downregulated and switched to the splice variant isoform that codes for the COOH-terminal leucine zipper motif. This was associated with increased sensitivity of the main UA and its subbranches to the vasorelaxant effects of the NO donor drug sodium nitroprusside. This difference was abolished by pretreatment with the phosphatase inhibitor tautomycetin. The sensitivity of relaxation to the NO second messenger cGMP was also increased under calcium-clamp conditions in permeabilized UAs, indicating heightened activation of MP. The changes in MP expression in HtP were largely prevented by treatment with the antihypertensive medicine hydralazine. We propose that MYPT1 isoform switching is an adaptive response to reduce vascular resistance and maintain uterine blood flow in the setting of hypertension-triggered inward remodeling of the UAs in hypertension of pregnancy.
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Affiliation(s)
- Yuan Lu
- Department of Medicine, Case Western Reserve School of Medicine, Cleveland, OH 44106-7290, USA
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Osol G, Gokina N, VanWoert K, Mandala M, Fisher S, Lu Y. PHENOTYPIC MODULATION OF VSM cGMP SIGNALING AND MYPT1 ISOFORM EXPRESSION BY NO INHIBITION DURING PREGNANCY. FASEB J 2006. [DOI: 10.1096/fasebj.20.4.a405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- George Osol
- Ob/GynUniv of Vermont College of MedicineBurlingtonVT05405
| | - Natalia Gokina
- Ob/GynUniv of Vermont College of MedicineBurlingtonVT05405
| | | | | | - Steven Fisher
- PhysiologyCase Western Reserve School of MedicineClevelandOH44106
| | - Yuan Lu
- PhysiologyCase Western Reserve School of MedicineClevelandOH44106
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Mandalà M, Gokina N, Osol G. Contribution of nonendothelial nitric oxide to altered rat uterine resistance artery serotonin reactivity during pregnancy. Am J Obstet Gynecol 2002; 187:463-8. [PMID: 12193944 DOI: 10.1067/mob.2002.123894] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE The aims of this study were to evaluate the effects of pregnancy on the serotonin reactivity of the mesometrial arteries and to assess the relative contribution of endothelial and smooth muscle cells to the overall effect. STUDY DESIGN Arteries were obtained from nonpregnant (n = 20) and late pregnant (n = 28) Sprague-Dawley rats and were cannulated in the chamber of an arteriograph. Changes in lumen diameter were measured by a video dimension analyzer. Statistical analysis used 2-way analysis of variance, followed by Bonferroni test. RESULTS Intact vessels from late pregnant versus nonpregnant animals were significantly less sensitive to the constrictor effects of serotonin at concentrations <100 nmol/L. A role for endothelial nitric oxide was indicated on the basis of the effects of denudation and N(omega)-nitro-L-arginine. Furthermore, the additional effect of N(omega)-nitro-L-arginine in denuded vessels from pregnant animals suggests that another, nonendothelial source of nitric oxide also contributes to the effect. CONCLUSION Pregnancy significantly decreases uterine resistance artery sensitivity to serotonin. This difference in sensitivity is due to the enhanced production of nitric oxide by endothelial cells and, most likely, by vascular smooth muscle.
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Affiliation(s)
- Maurizio Mandalà
- Department of Obstetrics and Gynecology, University of Vermont College of Medicine. Burlington, 05405, USA
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