Effects of superoxide and peroxynitrite on vascular tension in the human umbilical artery

Okatani, Yuji; Watanabe, Keiji; Wakatsuki, Akihiko; Tamura, S.; Sagara, Yusuke

doi:10.1080/j.1600-0412.1998.770902.x

Cited by 9 publications

(9 citation statements)

References 18 publications

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“…H 2 O 2 is rapidly converted to OH via the Fenton reaction in the presence of endogenous transition metal, especially Fe 2 + . We previously found that O 2 − generated by hypoxanthine and xanthine oxidase-elicited vasoconstriction in the human umbilical artery [Okatani et al, 1998a]. Pretreatment with hypoxanthine and xanthine oxidase significantly inhibited the vasorelaxant effect of A 23187.…”

Section: Discussionmentioning

confidence: 94%

“…However, Simon et al [1990] and Murohara et al [1994] have demonstrated that O 2 − scavenger superoxide dismutase (SOD) failed to inhibit the vasoconstriction induced by ox-LDL or LPC in isolated porcine coronary arteries. In a previous study, we found that the ONOO − produced by 3-morpholinosydnonimine (SIN-1) induced vasorelaxation in isolated human umbilical artery [Okatani et al, 1998a[Okatani et al, , 1999. These findings suggest that the O 2 − -mediated degradation of NO or O 2 − generation via reverse SOD reaction is not likely to be responsible for the vasospastic action of LPC.…”

Section: Discussionmentioning

confidence: 99%

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Attenuation by melatonin of human umbilical arterial vasoconstriction induced by lysophosphatidylcholine

Okatani

Wakatsuki²,

Watanabe³

et al. 2000

Journal of Pineal Research

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We evaluated the antioxidant property of melatonin as related to the vasospastic effect of lysophosphatidylcholine (LPC), a component of oxidized lipoprotein, on the human umbilical artery. Helical sections of umbilical arteries were obtained from healthy pregnant women who were delivered between 37 and 39 wk of gestation. Changes in maximal tension induced by KCl were measured in arterial sections having intact endothelium. Sections were treated with LPC alone (15 or 30 microM), or were pretreated either with a hydrogen peroxide (H2O2) scavenger (catalase, 1,200 U/mL), a hydroxyl radical scavenger (mannitol, 30 mM), a nitric oxide (NO) synthesis inhibitor (L-N(G)-monomethyl arginine, LNMA, 2 x 10(-4) M) or melatonin (1 or 10 microM). The effect of LPC (30 microM) on the vasorelaxation induced by 5-hydroxytryptamine (5-HT) was also determined, with or without melatonin pretreatment (10 microM). LPC potentiated vascular tension in a concentration-dependent manner. Pretreatment with LNMA significantly suppressed this vasospastic effect of LPC. Pretreatment with catalase or mannitol significantly reduced the vasospastic effect of LPC. Melatonin significantly lessened the vasospastic effect of LPC in a concentration-dependent manner. Pretreatment with LPC significantly inhibited the relaxation induced by 5-HT. Treatment with melatonin prior to LPC exposure significantly restored the relaxation induced by 5-HT. Results suggest that LPC potentiates vascular tension in human umbilical artery, perhaps by suppressing the endothelial synthesis of NO. Melatonin significantly suppressed the vasospastic effect of LPC. This agent probably scavenges the hydroxyl radicals arising from LPC.

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Section: Discussionmentioning

confidence: 94%

Section: Discussionmentioning

confidence: 99%

Attenuation by melatonin of human umbilical arterial vasoconstriction induced by lysophosphatidylcholine

Okatani

Wakatsuki²,

Watanabe³

et al. 2000

Journal of Pineal Research

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“…Under increased tension conditions induced by potassium chloride, the authors demonstrated that superoxide is a potent vasoconstrictor, whereas PN is a vasodilator. The authors suggested that the vasorelaxation induced by exogenously PN in this model has biological relevance in the regulation of the human umbilical artery [187]. Subsequent studies in this model demonstrated that the administration of melatonin reduced the vasorelaxant properties of SIN-1, 3-morpholinosydomine, a sydnonimine that is known to release superoxide and NO, and form PN under physiological conditions [58,188].…”

Section: Vasorelaxant Properties Of Peroxyni-tritementioning

confidence: 99%

“…In addition to toxic effects, PN may also act as an endogenous modulator of endothelial cell function [21,23]. Okatani, Watanabe et al evaluated the role of superoxide and of PN in regulating tone in the human fetoplacental vasculature [187]. In this study, helical sections of human umbilical arteries with intact endothelium were obtained from healthy pregnant women.…”

Section: Vasorelaxant Properties Of Peroxyni-tritementioning

confidence: 99%

Potential Benefits of Peroxynitrite

Nossaman

Kadowitz²

2008

TOPHARMJ

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Peroxynitrite (PN) is generated by the reaction of nitric oxide (NO) and superoxide in one of the most rapid reactions in biology. Studies have reported that PN is a cytotoxic molecule that contributes to vascular injury in a number of disease states. However, it has become apparent that PN has beneficial effects including vasodilation, inhibition of platelet aggregation, inhibition of inflammatory cell adhesion, and protection against ischemia/reperfusion injury in the heart. It is our hypothesis that PN may serve to inactivate superoxide and prolong the actions of NO in the circulation. This manuscript reviews the beneficial effects of PN in the cardiovascular system. Keywords:Nitric oxide/*metabolism, nitric oxide synthase/metabolism/physiology, peroxynitrous acid/metabolism, reactive nitrogen species/metabolism, reactive oxygen species/metabolism, endothelium, vascular/drug effects/metabolism, muscle, smooth, vascular/drug effects/*metabolism, vasodilator agents/adverse effects, oxidative stress/*physiology, vasodilation/drug effects.

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“…We previously have shown that vascular tension in the human umbilical artery is potentiated by hydrogen peroxide and superoxide (O 2 − ) and may be mediated by suppression of production of NO and prostacyclin, which are endothelially derived relaxing factors (EDRF) [Okatani et al 1997a[Okatani et al , 1998a. Furthermore, we have found that melatonin inhibits the vasospastic effect of OH in the human umbilical artery in vitro, possibly as a result of its ability to scavenge OH [Okatani et al, 1997b,c].…”

Section: Introductionmentioning

confidence: 99%

Melatonin inhibits vasospastic action of oxidized low‐density lipoprotein in human umbilical arteries

Okatani

Wakatsuki²,

Watanabe³

et al. 2000

Journal of Pineal Research

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We evaluated the antioxidant property of melatonin in countering the vasospastic effect of oxidized low-density lipoprotein (ox-LDL), which has been reported to be the most important risk factor for atherosclerosis and also may be linked to preeclampsia. Helical sections of umbilical arteries were obtained from human placentas at elective cesarean deliveries between 37 and 39 weeks of gestation. Changes in maximal tension induced by potassium chloride were measured in arterial sections with intact endothelium. ox-LDL (200 or 300 microg protein/mL) increased vascular tension by 15.6 +/- 2.3 or 31.9 +/- 4.0%, respectively. In contrast, native LDL only slightly increased vascular tension (2.7 +/- 1.0% for 200 microg protein/mL and 6.0 +/- 1.7% for 300 microg protein/mL). Pretreatment with L-N(G)-monomethyl-arginine (2 x 10(-4) M) significantly reduced the vasospastic effect of ox-LDL, as did pretreatment with mannitol (30 mM). Melatonin (10 microM) significantly reduced the vasospastic effect of ox-LDL. These findings suggest that ox-LDL potentiates vascular tension in the human umbilical artery, possibly by suppressing endothelial synthesis of nitric oxide. Melatonin significantly suppressed the vasospastic effect of ox-LDL, probably because it scavenges hydroxyl radical arising from ox-LDL.

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Effects of superoxide and peroxynitrite on vascular tension in the human umbilical artery

Cited by 9 publications

References 18 publications

Attenuation by melatonin of human umbilical arterial vasoconstriction induced by lysophosphatidylcholine

Attenuation by melatonin of human umbilical arterial vasoconstriction induced by lysophosphatidylcholine

Potential Benefits of Peroxynitrite

Melatonin inhibits vasospastic action of oxidized low‐density lipoprotein in human umbilical arteries

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