Effects of a novel guanylyl cyclase inhibitor on the vascular actions of nitric oxide and peroxynitrite in immunostimulated smooth muscle cells and in endotoxic shock

Basilia Zingarelli, György Haskó, Andrew L. Salzman, Csaba Szabo

Research output: Contribution to journalArticle

42 Citations (Scopus)

Abstract

Objective: Nitric oxide (NO), produced by the inducible isoform of NO synthase (NOS) in circulatory shock exerts cytotoxic and vasodilator effects. Part of these effects are mediated by formation of peroxynitrite, a toxic oxidant produced by the rapid reaction of NO and superoxide. Other parts of the vascular actions of NO in shock are thought to be mediated by the action of NO on the soluble guanylyl cyclase (GC) in the smooth muscle and subsequent decrease in the intracellular calcium levels. Using 1H(1,2,4)oxadiazolo(4,3-α)quinoxalin-1-one (ODQ), a potent inhibitor of GC, we studied the role of GC activation in the NO- and peroxynitrite-related vascular alterations. Design: In vitro: Controlled experiment using cultured rat aortic smooth muscle cells. In vivo. Prospective, randomized, controlled animal study. Setting: Experimental laboratory. Subjects: Male Wistar rats and male Swiss mice. Interventions: In vitro: a) Stimulation of rat aortic smooth muscle cells with bacterial lipopolysaccharide (LPS) and γ- interferon, measurement of the production of nitrite and nitrate (breakdown products of NO), and suppression of mitochondrial respiration for 24 to 48 hrs, in the presence or absence of ODQ; and b) in norepinephrine- precontracted endothelium-denuded thoracic aortic rings, exposure to LPS (10 ng/mL) in the presence or absence of ODQ. In vivo: Rats treated in vivo with LPS (10 mg/kg iv for 3 hrs) and mice challenged with 60 mg/kg LPS ip, in the presence or absence of ODQ. Measurements and Main Results: Stimulation of rat aortic smooth muscle cells with bacterial LPS and γ-interferon induced the production of nitrite and nitrate (breakdown products of NO) and suppression of mitochondrial respiration for 24 to 48 hrs. The amount of NO produced was slightly enhanced with ODQ (10-100 μM), whereas the suppression of mitochondrial respiration was not affected by ODQ (1-100 μM). ODQ did not affect the degree of suppression of mitochondrial respiration in response to NO donor agents or to peroxynitrite. Exposure to LPS (10 ng/mL) for 6 hrs caused a time-dependent relaxation of norepinephrine-precontracted endothelium-denuded thoracic aortic rings. This response was caused by the expression of inducible NOS and could be blocked by pharmacologic inhibitors of NOS such as N(G)-methyl-L-arginine. ODQ (1 μM) prevented the LPS-induced loss of vascular tone in this experimental system. Similar to the in vitro responses, there was a significant suppression of the norepinephrine-induced contractions in ex vivo experiments, in which rings were taken from animals treated in vivo with LPS (10 mg/kg for 3 hrs). ODQ treatment in vitro (1 μM) caused a complete restoration of the contractile responses. In mice challenged with 60 mg/kg LPS ip, ODQ (20 mg/kg), given either as a pretreatment or as a 4-hr posttreatment, improved survival at 24-144 hrs. Conclusion: These studies indicate that GC activation does not contribute to NO- or peroxynitrite-induced cytotoxicity but does contribute to the vascular hyporeactivity induced by endotoxin in vitro and in vivo. GC inhibition alone is sufficient to influence survival in a murine model of severe sepsis.

Original languageEnglish (US)
Pages (from-to)1701-1707
Number of pages7
JournalCritical Care Medicine
Volume27
Issue number9
DOIs
StatePublished - 1999
Externally publishedYes

Fingerprint

Peroxynitrous Acid
Guanylate Cyclase
Septic Shock
Smooth Muscle Myocytes
Blood Vessels
Lipopolysaccharides
Nitric Oxide
Respiration
Norepinephrine
Nitrites
Nitric Oxide Synthase
Nitrates
Interferons
Endothelium
Shock
Thorax
Quinoxalines
Nitric Oxide Donors
Poisons
Nitric Oxide Synthase Type II

Keywords

  • Contractility
  • Inflammation
  • Interferon
  • Lipopolysaccharide
  • Nitric oxide
  • Peroxynitrite
  • Raperfusion
  • Sepsis
  • Su rvival
  • Vascular

ASJC Scopus subject areas

  • Critical Care and Intensive Care Medicine

Cite this

Effects of a novel guanylyl cyclase inhibitor on the vascular actions of nitric oxide and peroxynitrite in immunostimulated smooth muscle cells and in endotoxic shock. / Zingarelli, Basilia; Haskó, György; Salzman, Andrew L.; Szabo, Csaba.

In: Critical Care Medicine, Vol. 27, No. 9, 1999, p. 1701-1707.

Research output: Contribution to journalArticle

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abstract = "Objective: Nitric oxide (NO), produced by the inducible isoform of NO synthase (NOS) in circulatory shock exerts cytotoxic and vasodilator effects. Part of these effects are mediated by formation of peroxynitrite, a toxic oxidant produced by the rapid reaction of NO and superoxide. Other parts of the vascular actions of NO in shock are thought to be mediated by the action of NO on the soluble guanylyl cyclase (GC) in the smooth muscle and subsequent decrease in the intracellular calcium levels. Using 1H(1,2,4)oxadiazolo(4,3-α)quinoxalin-1-one (ODQ), a potent inhibitor of GC, we studied the role of GC activation in the NO- and peroxynitrite-related vascular alterations. Design: In vitro: Controlled experiment using cultured rat aortic smooth muscle cells. In vivo. Prospective, randomized, controlled animal study. Setting: Experimental laboratory. Subjects: Male Wistar rats and male Swiss mice. Interventions: In vitro: a) Stimulation of rat aortic smooth muscle cells with bacterial lipopolysaccharide (LPS) and γ- interferon, measurement of the production of nitrite and nitrate (breakdown products of NO), and suppression of mitochondrial respiration for 24 to 48 hrs, in the presence or absence of ODQ; and b) in norepinephrine- precontracted endothelium-denuded thoracic aortic rings, exposure to LPS (10 ng/mL) in the presence or absence of ODQ. In vivo: Rats treated in vivo with LPS (10 mg/kg iv for 3 hrs) and mice challenged with 60 mg/kg LPS ip, in the presence or absence of ODQ. Measurements and Main Results: Stimulation of rat aortic smooth muscle cells with bacterial LPS and γ-interferon induced the production of nitrite and nitrate (breakdown products of NO) and suppression of mitochondrial respiration for 24 to 48 hrs. The amount of NO produced was slightly enhanced with ODQ (10-100 μM), whereas the suppression of mitochondrial respiration was not affected by ODQ (1-100 μM). ODQ did not affect the degree of suppression of mitochondrial respiration in response to NO donor agents or to peroxynitrite. Exposure to LPS (10 ng/mL) for 6 hrs caused a time-dependent relaxation of norepinephrine-precontracted endothelium-denuded thoracic aortic rings. This response was caused by the expression of inducible NOS and could be blocked by pharmacologic inhibitors of NOS such as N(G)-methyl-L-arginine. ODQ (1 μM) prevented the LPS-induced loss of vascular tone in this experimental system. Similar to the in vitro responses, there was a significant suppression of the norepinephrine-induced contractions in ex vivo experiments, in which rings were taken from animals treated in vivo with LPS (10 mg/kg for 3 hrs). ODQ treatment in vitro (1 μM) caused a complete restoration of the contractile responses. In mice challenged with 60 mg/kg LPS ip, ODQ (20 mg/kg), given either as a pretreatment or as a 4-hr posttreatment, improved survival at 24-144 hrs. Conclusion: These studies indicate that GC activation does not contribute to NO- or peroxynitrite-induced cytotoxicity but does contribute to the vascular hyporeactivity induced by endotoxin in vitro and in vivo. GC inhibition alone is sufficient to influence survival in a murine model of severe sepsis.",
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year = "1999",
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TY - JOUR

T1 - Effects of a novel guanylyl cyclase inhibitor on the vascular actions of nitric oxide and peroxynitrite in immunostimulated smooth muscle cells and in endotoxic shock

AU - Zingarelli, Basilia

AU - Haskó, György

AU - Salzman, Andrew L.

AU - Szabo, Csaba

PY - 1999

Y1 - 1999

N2 - Objective: Nitric oxide (NO), produced by the inducible isoform of NO synthase (NOS) in circulatory shock exerts cytotoxic and vasodilator effects. Part of these effects are mediated by formation of peroxynitrite, a toxic oxidant produced by the rapid reaction of NO and superoxide. Other parts of the vascular actions of NO in shock are thought to be mediated by the action of NO on the soluble guanylyl cyclase (GC) in the smooth muscle and subsequent decrease in the intracellular calcium levels. Using 1H(1,2,4)oxadiazolo(4,3-α)quinoxalin-1-one (ODQ), a potent inhibitor of GC, we studied the role of GC activation in the NO- and peroxynitrite-related vascular alterations. Design: In vitro: Controlled experiment using cultured rat aortic smooth muscle cells. In vivo. Prospective, randomized, controlled animal study. Setting: Experimental laboratory. Subjects: Male Wistar rats and male Swiss mice. Interventions: In vitro: a) Stimulation of rat aortic smooth muscle cells with bacterial lipopolysaccharide (LPS) and γ- interferon, measurement of the production of nitrite and nitrate (breakdown products of NO), and suppression of mitochondrial respiration for 24 to 48 hrs, in the presence or absence of ODQ; and b) in norepinephrine- precontracted endothelium-denuded thoracic aortic rings, exposure to LPS (10 ng/mL) in the presence or absence of ODQ. In vivo: Rats treated in vivo with LPS (10 mg/kg iv for 3 hrs) and mice challenged with 60 mg/kg LPS ip, in the presence or absence of ODQ. Measurements and Main Results: Stimulation of rat aortic smooth muscle cells with bacterial LPS and γ-interferon induced the production of nitrite and nitrate (breakdown products of NO) and suppression of mitochondrial respiration for 24 to 48 hrs. The amount of NO produced was slightly enhanced with ODQ (10-100 μM), whereas the suppression of mitochondrial respiration was not affected by ODQ (1-100 μM). ODQ did not affect the degree of suppression of mitochondrial respiration in response to NO donor agents or to peroxynitrite. Exposure to LPS (10 ng/mL) for 6 hrs caused a time-dependent relaxation of norepinephrine-precontracted endothelium-denuded thoracic aortic rings. This response was caused by the expression of inducible NOS and could be blocked by pharmacologic inhibitors of NOS such as N(G)-methyl-L-arginine. ODQ (1 μM) prevented the LPS-induced loss of vascular tone in this experimental system. Similar to the in vitro responses, there was a significant suppression of the norepinephrine-induced contractions in ex vivo experiments, in which rings were taken from animals treated in vivo with LPS (10 mg/kg for 3 hrs). ODQ treatment in vitro (1 μM) caused a complete restoration of the contractile responses. In mice challenged with 60 mg/kg LPS ip, ODQ (20 mg/kg), given either as a pretreatment or as a 4-hr posttreatment, improved survival at 24-144 hrs. Conclusion: These studies indicate that GC activation does not contribute to NO- or peroxynitrite-induced cytotoxicity but does contribute to the vascular hyporeactivity induced by endotoxin in vitro and in vivo. GC inhibition alone is sufficient to influence survival in a murine model of severe sepsis.

AB - Objective: Nitric oxide (NO), produced by the inducible isoform of NO synthase (NOS) in circulatory shock exerts cytotoxic and vasodilator effects. Part of these effects are mediated by formation of peroxynitrite, a toxic oxidant produced by the rapid reaction of NO and superoxide. Other parts of the vascular actions of NO in shock are thought to be mediated by the action of NO on the soluble guanylyl cyclase (GC) in the smooth muscle and subsequent decrease in the intracellular calcium levels. Using 1H(1,2,4)oxadiazolo(4,3-α)quinoxalin-1-one (ODQ), a potent inhibitor of GC, we studied the role of GC activation in the NO- and peroxynitrite-related vascular alterations. Design: In vitro: Controlled experiment using cultured rat aortic smooth muscle cells. In vivo. Prospective, randomized, controlled animal study. Setting: Experimental laboratory. Subjects: Male Wistar rats and male Swiss mice. Interventions: In vitro: a) Stimulation of rat aortic smooth muscle cells with bacterial lipopolysaccharide (LPS) and γ- interferon, measurement of the production of nitrite and nitrate (breakdown products of NO), and suppression of mitochondrial respiration for 24 to 48 hrs, in the presence or absence of ODQ; and b) in norepinephrine- precontracted endothelium-denuded thoracic aortic rings, exposure to LPS (10 ng/mL) in the presence or absence of ODQ. In vivo: Rats treated in vivo with LPS (10 mg/kg iv for 3 hrs) and mice challenged with 60 mg/kg LPS ip, in the presence or absence of ODQ. Measurements and Main Results: Stimulation of rat aortic smooth muscle cells with bacterial LPS and γ-interferon induced the production of nitrite and nitrate (breakdown products of NO) and suppression of mitochondrial respiration for 24 to 48 hrs. The amount of NO produced was slightly enhanced with ODQ (10-100 μM), whereas the suppression of mitochondrial respiration was not affected by ODQ (1-100 μM). ODQ did not affect the degree of suppression of mitochondrial respiration in response to NO donor agents or to peroxynitrite. Exposure to LPS (10 ng/mL) for 6 hrs caused a time-dependent relaxation of norepinephrine-precontracted endothelium-denuded thoracic aortic rings. This response was caused by the expression of inducible NOS and could be blocked by pharmacologic inhibitors of NOS such as N(G)-methyl-L-arginine. ODQ (1 μM) prevented the LPS-induced loss of vascular tone in this experimental system. Similar to the in vitro responses, there was a significant suppression of the norepinephrine-induced contractions in ex vivo experiments, in which rings were taken from animals treated in vivo with LPS (10 mg/kg for 3 hrs). ODQ treatment in vitro (1 μM) caused a complete restoration of the contractile responses. In mice challenged with 60 mg/kg LPS ip, ODQ (20 mg/kg), given either as a pretreatment or as a 4-hr posttreatment, improved survival at 24-144 hrs. Conclusion: These studies indicate that GC activation does not contribute to NO- or peroxynitrite-induced cytotoxicity but does contribute to the vascular hyporeactivity induced by endotoxin in vitro and in vivo. GC inhibition alone is sufficient to influence survival in a murine model of severe sepsis.

KW - Contractility

KW - Inflammation

KW - Interferon

KW - Lipopolysaccharide

KW - Nitric oxide

KW - Peroxynitrite

KW - Raperfusion

KW - Sepsis

KW - Su rvival

KW - Vascular

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U2 - 10.1097/00003246-199909000-00001

DO - 10.1097/00003246-199909000-00001

M3 - Article

C2 - 10507586

AN - SCOPUS:0032879115

VL - 27

SP - 1701

EP - 1707

JO - Critical Care Medicine

JF - Critical Care Medicine

SN - 0090-3493

IS - 9

ER -