Fetoplacental vascular tone is modified by magnesium sulfate in the preeclamptic ex vivo human placental cotyledon

Kovac, Christine; Howard, Bobby; Pierce, Brian; Hoeldtke, Nathan J.; Calhoun, Byron C.; Napolitano, Peter G.

doi:10.1067/s0002-9378(03)00851-2

Cited by 18 publications

(12 citation statements)

References 18 publications

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“…This suggested that vascular functions in response to MgSO 4 in the preeclampsia placenta were similar to that of the control, proving the evidence that the drug only could relieve the hypertension symptoms in the patients by reducing increased blood pressure, while being unable to prevent the fundamental causes of preeclampsia . We noted that a previous study reported that when exposing to MgSO 4 , the perfusion pressure was decreased in the preeclampsia but not in the control pregnancy 8. The difference between their results and ours could be caused by different experimental subjects: placental organ perfusion versus isolated vessel tension.…”

Section: Discussioncontrasting

confidence: 83%

“…The presence or absence of connective tissue surrounding placental vessels was a critical difference in the 2 settings. Combining both results, analysis suggests that MgSO 4 also may have indirect special effects via the tissue outside PV, decreasing placental perfusion in preeclampsia as has been reported 8. However, there is a critical issue that cannot be explained.…”

Section: Discussionmentioning

confidence: 62%

“…Fetal–placental circulation is not innervated and vascular tone is mainly controlled by autocrine or paracrine factors 5. Previous studies reported that MgSO 4 had significant direct effects on fetal–placental circulation 4, 6, 7, 8. However, whether MgSO 4 produces the same or different vascular dilations in the placenta is largely unknown.…”

Section: Introductionmentioning

confidence: 99%

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Magnesium Sulfate–Mediated Vascular Relaxation and Calcium Channel Activity in Placental Vessels Different From Nonplacental Vessels

Tang

et al. 2018

JAHA

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BackgroundMagnesium sulfate (MgSO 4) has been used as a common therapy for preeclampsia and eclampsia for many years. MgSO 4 decreases peripheral vascular resistance so as to reduce maternal blood pressure. Whether placental blood vessels react to MgSO 4 in the same patterns as that in maternal vessels is largely unknown.Methods and ResultsThis study compared placental vessels (PV) versus nonplacental vessels (non‐PV) in human and animal models. MgSO 4‐caused vascular dilation was significantly weaker in PV than that in non‐PV. Prostaglandin I2 synthetase affected MgSO 4‐mediated vasodilatation in PV, not in umbilical vessels, while cyclooxygenase did not influence MgSO 4‐induced relaxation in both PV and non‐PV. Mg2+‐caused vasodilatation was mainly through calcium channels. In PV, calcium channel activities were significantly weaker in PV than that in non‐PV. Relative mRNA expression of CACNA1D,CACNB2, and CACNB3 was significantly higher in PV than those in umbilical vessels, despite the fact that the expression of CACNA1F was less in PV. The contractile phenotype of smooth muscle cell marker (CALD1) was less and the synthetic phenotype (MYH10) was more in PV than that in UV.ConclusionsThese results demonstrated that PV were characterized by much weaker responses to MgSO 4 compared with nonplacental vessels. The difference was related to weaker calcium channel activity and minor contractile phenotype smooth muscle cells in PV, providing important information for further understanding treatments with MgSO 4 in preeclampsia.

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Section: Discussioncontrasting

confidence: 83%

Section: Discussionmentioning

confidence: 62%

Section: Introductionmentioning

confidence: 99%

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Magnesium Sulfate–Mediated Vascular Relaxation and Calcium Channel Activity in Placental Vessels Different From Nonplacental Vessels

Tang

et al. 2018

JAHA

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“…The reduction of circulating antiangiogenic factors in the PRE þ MgSO 4 group in the current study could be explained by the ability of MgSO 4 to decrease systemic vascular resistance and counteract the vasoconstrictor substances in several vascular beds. 28 Furthermore, MgSO 4 was reported to decrease feto-placental perfusion pressure 43 and depress the expression of caspase-3 in the placenta. 44 These effects are anticipated to improve placental blood flow and relieve the ischemia and subsequently decrease the production of sFlt-1 and ENG.…”

Section: Discussionmentioning

confidence: 99%

Magnesium sulfate therapy of preeclampsia: an old tool with new mechanism of action and prospect in management and prophylaxis

Korish

2012

Hypertens Res

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A disturbed balance between angiogenic and antiangiogenic growth factors is a highly accepted mechanism in the pathogenesis of pregnancy-induced hypertension and proteinuria, which is clinically known as preeclampsia (PE). We investigated the effect of magnesium sulfate (MgSO 4 ) therapy on vascular endothelial growth factor (VEGF), placental growth factor (PlGF), nitric oxide (NO) metabolites, soluble fm-like tyrosine kinase-1 (sFlt-1) and endoglin levels in PE rats and the effect of this treatment on the feto-maternal outcome. The PE group showed hypertension, proteinuria and decreased number and weight of live pups relative to the control group. This result was associated with increased sFlt-1, VEGF receptor-2 (VEGFR-2), VEGFR-3 and endoglin levels but decreased NO metabolites. MgSO 4 therapy ameliorated systolic hypertension and proteinuria and decreased sFlt-1, VEGFR-2, VEGFR-3 and endoglin levels but increased NO metabolites in the treated group. Physiological and biochemical changes and improved pup weight and viability were observed in the treated group. The vasodilator action of MgSO 4 and increased NO production are expected to increase placental blood flow and help fetal nutrition and development. Relief of placental ischemia decreases the production of antiangiogenic growth factors and restores the bioavailability of angiogenic factors (PlGF and VEGF). These changes resulted in better fetal outcome and an improved clinical picture of PE. These findings are promising and encourage further study of the mechanism of action of MgSO 4 to support its widespread use in the prevention and management of the etiopathological changes underlying the vast majority of the manifestations and complications of PE.

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“…Enquanto em alguns estudos se observam uma redução significativa na pressão arterial e nos índices dopplervelocimétricos das artérias uterinas, umbilical e cerebral média do feto, em outros são encontrados resultados contrários a esta afirmação [13][14][15][16][17] . Todavia, sabe-se que o magnésio pode exercer algum efeito sobre a circulação materna e fetal.…”

Section: Doppler Das Artérias Umbilicais E Cerebral Média Fetal Após unclassified

Doppler das artérias umbilicais e cerebral média fetal após sulfato de magnésio na pré-eclâmpsia

Souza¹,

Amorim²,

Coelho³

et al. 2008

Rev. Assoc. Med. Bras.

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RESUMO OBJETIVO.Comparar a relação da artéria umbilical e artéria cerebral média fetal através dos índices dopplervelocimétricos (índice de resistência, índice de pulsatilidade e relação S/D) antes e após a utilização do sulfato de magnésio nas gestantes com pré-eclâmpsia grave (pura ou superposta). MÉTODOS. Foi desenvolvido um estudo do tipo coorte prospectivo, no qual cada sujeito serviu como seu próprio controle. Foram selecionadas 40 gestantes com pré-eclâmpsia grave, submetidas ao exame dopplervelocimétrico antes e após 20 minutos da administração intravenosa de 6 g do sulfato de magnésio. As variáveis estudadas foram os índices dopplervelocimétricos da relação artéria umbilical e cerebral média fetal. A comparação das médias entre as duas medidas (antes e depois) de cada indivíduo foi realizada através do teste t student pareado. A comparação entre a distribuição de freqüência de diagnóstico fetal (normal, redução isolada na resistência da artéria cerebral média e centralizado) foi realizada através do teste Qui quadrado (χ 2 ) de Stuart-Maxwell. RESULTADOS. Não foi observada diferença estatisticamente significativa das médias da relação artéria umbilical/cerebral média nos índices dopplervelocimétricos antes e após o sulfato de magnésio. Verificou-se aumento da freqüência de redução isolada na resistência da artéria cerebral média após o sulfato de magnésio (25,0% x 47,5%; p = 0,01). CONCLUSÃO. A administração intravenosa do sulfato de magnésio nas gestantes com pré-eclâmpsia grave resultou em um aumento significativo na freqüência de fetos com diagnóstico de redução da resistência da artéria cerebral média na dopplervelocimetria.UNITERMOS: Hipertensão. Artérias umbilicais. Artéria cerebral média. Ultra-sonografia Doppler. Pré-eclâmpsia. Sulfato de magnésio. DOPPLER DAS ARTÉRIAS UMBILICAIS E CEREBRAL MÉDIA FETAL APÓS SULFATO INTRODUÇÃOO sulfato de magnésio firmou-se como importante medida terapêutica adotada nas pacientes com pré-eclâmpsia/eclâmpsia, sendo largamente estudado e reconhecido como a droga de escolha, não apenas para a profilaxia, mas também para o tratamento das convulsões eclâmpticas. Ensaios clínicos multicêntricos e revisões sistemáticas asseguram a efetividade e a segurança do sulfato de magnésio na redução significativa do risco de convulsões e no risco de morte materna [1][2][3][4][5][6] . O magnésio é o mais abundante e importante cátion bivalente intracelular, responsável por diversas funções. Credita-se a este cátion o importante papel na regulação da pressão sangüínea através da modulação da reatividade do tono vascular e da resistência periférica total 7,8,9 . O aumento na concentração do magnésio extracelular resulta em vasodilatação, atenuando os agonistas que induzem a vasoconstrição. Nas situações em que as concentrações estão reduzidas, ocorre uma vasoconstrição com potencialização dos agonistas, resultando na vasoconstrição. O mecanismo exato deste processo é incerto, mas acredita-se que é influenciado pelas concentrações de Ca 2+ , o maior determinante da contração do músc...

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Fetoplacental vascular tone is modified by magnesium sulfate in the preeclamptic ex vivo human placental cotyledon

Cited by 18 publications

References 18 publications

Magnesium Sulfate–Mediated Vascular Relaxation and Calcium Channel Activity in Placental Vessels Different From Nonplacental Vessels

Magnesium Sulfate–Mediated Vascular Relaxation and Calcium Channel Activity in Placental Vessels Different From Nonplacental Vessels

Magnesium sulfate therapy of preeclampsia: an old tool with new mechanism of action and prospect in management and prophylaxis

Doppler das artérias umbilicais e cerebral média fetal após sulfato de magnésio na pré-eclâmpsia

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