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Sphingosylphosphorylcholine potentiates vasoreactivity and voltage-gated Ca2+ entry via NOX1 and reactive oxygen species.

Shaifta Y, Snetkov VA, Prieto-Lloret J, Knock GA, Smirnov SV, Aaronson PI, Ward JP - Cardiovasc. Res. (2015)

Bottom Line: The intracellular superoxide generator LY83583 mimicked the effect of SPC.In patch-clamped mesenteric artery cells, SPC (200 nmol/L) enhanced Ba2+ current through L-type Ca2+ channels, an action abolished by Tempol but mimicked by LY83583.Our results suggest that low concentrations of SPC activate a PLC-coupled and NOX1-mediated increase in ROS, with consequent enhancement of voltage-gated Ca2+ entry and thus vasoreactivity.

View Article: PubMed Central - PubMed

Affiliation: Division of Asthma, Allergy, and Lung Biology, King's College London, 5th Floor Tower Wing, Guy's Campus, London SE1 9RT, UK.

No MeSH data available.


Related in: MedlinePlus

U46619 and SPC-induced contraction, and effects of Tempol and nifedipine. (A) Cumulative concentration–response curves for U46619: control (filled circle), SPC (1 µmol/L; open circle), SPC + Tempol (open square); 12 MA (6 rats). Tempol alone (filled square); n = 8 MA (4 rats). Mean pD2: control: 7.11 ± 0.02; SPC: 7.53 ± 0.03, P < 0.001 vs. control; SPC + Tempol: 6.99 ± 0.02, P < 0.001 vs. SPC, P < 0.02 vs. control; RM ANOVA, Holm-Sidak post hoc. pD2 for Tempol alone: 6.90 ± 0.08, NS vs. Tempol + SPC; P < 0.05 vs. Control; one-way ANOVA, Holm-Sidak post hoc. Bars = SEM. (B) Similar to A, but in the presence of nifedipine (3 µmol/L; open square), and SPC + nifedipine (filled square); 15 MA (9 rats). Control: pD2: 7.04 ± 0.06, Vmax: 144 ± 13% KPSS; nifedipine: pD2: 6.64 ± 0.05, P < 0.001 vs. control, Vmax: 43 ± 5% KPSS, P < 0.001 vs. control; SPC + nifedipine: pD2: 6.67 ± 0.03, NS vs. nifedipine alone, Vmax: 53 ± 6% KPSS, NS vs. nifedipine alone; RM ANOVA, Holm-Sidak post hoc. (C) Cumulative concentration–response curves for SPC in MA (filled circles); 16 MA (10 rats), with Tempol (filled squares); 8 MA (5 rats), or nifedipine (open squares); 10 MA (6 rats). SPC: pD2: 5.08 ± 0.04, Vmax: 16.8 ± 1.3% KPSS; SPC + Tempol: pD2: 4.84 ± 0.06, P < 0.02 vs. control, Vmax: 4.24 ± 1.2% KPSS, P < 0.001 vs. control; SPC + nifedipine: pD2: 5.10 ± 0.06, NS vs. control, Vmax: 8.25 ± 1.1% KPSS, P < 0.002 vs. control, P < 0.05 vs. Tempol; one-way ANOVA, Holm-Sidak post hoc. Bars = SEM (not shown if smaller than symbol).
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CVV029F4: U46619 and SPC-induced contraction, and effects of Tempol and nifedipine. (A) Cumulative concentration–response curves for U46619: control (filled circle), SPC (1 µmol/L; open circle), SPC + Tempol (open square); 12 MA (6 rats). Tempol alone (filled square); n = 8 MA (4 rats). Mean pD2: control: 7.11 ± 0.02; SPC: 7.53 ± 0.03, P < 0.001 vs. control; SPC + Tempol: 6.99 ± 0.02, P < 0.001 vs. SPC, P < 0.02 vs. control; RM ANOVA, Holm-Sidak post hoc. pD2 for Tempol alone: 6.90 ± 0.08, NS vs. Tempol + SPC; P < 0.05 vs. Control; one-way ANOVA, Holm-Sidak post hoc. Bars = SEM. (B) Similar to A, but in the presence of nifedipine (3 µmol/L; open square), and SPC + nifedipine (filled square); 15 MA (9 rats). Control: pD2: 7.04 ± 0.06, Vmax: 144 ± 13% KPSS; nifedipine: pD2: 6.64 ± 0.05, P < 0.001 vs. control, Vmax: 43 ± 5% KPSS, P < 0.001 vs. control; SPC + nifedipine: pD2: 6.67 ± 0.03, NS vs. nifedipine alone, Vmax: 53 ± 6% KPSS, NS vs. nifedipine alone; RM ANOVA, Holm-Sidak post hoc. (C) Cumulative concentration–response curves for SPC in MA (filled circles); 16 MA (10 rats), with Tempol (filled squares); 8 MA (5 rats), or nifedipine (open squares); 10 MA (6 rats). SPC: pD2: 5.08 ± 0.04, Vmax: 16.8 ± 1.3% KPSS; SPC + Tempol: pD2: 4.84 ± 0.06, P < 0.02 vs. control, Vmax: 4.24 ± 1.2% KPSS, P < 0.001 vs. control; SPC + nifedipine: pD2: 5.10 ± 0.06, NS vs. control, Vmax: 8.25 ± 1.1% KPSS, P < 0.002 vs. control, P < 0.05 vs. Tempol; one-way ANOVA, Holm-Sidak post hoc. Bars = SEM (not shown if smaller than symbol).

Mentions: We examined whether ROS were also responsible for SPC-induced potentiation of agonist-induced contraction. We utilized U46619, as unlike PGF2α it only activates TP receptors; experiments were performed in the presence of 100 µmol/L l-NAME to mitigate against any complicating effects of nitric oxide. U46619 concentration–response curves are repeatable; three were performed on each MA: control, following incubation with SPC (1 µmol/L), and SPC plus Tempol (3 mmol/L). A separate set of time-matched experiments were performed with Tempol alone. SPC caused a large leftward shift in the U46619 concentration–response relationship (P < 0.001), which was ablated in the presence of Tempol such that the relationship was shifted significantly to the right of control (P < 0.05; Figure 4A). There was no difference between the effects of SPC plus Tempol and Tempol alone.Figure 4


Sphingosylphosphorylcholine potentiates vasoreactivity and voltage-gated Ca2+ entry via NOX1 and reactive oxygen species.

Shaifta Y, Snetkov VA, Prieto-Lloret J, Knock GA, Smirnov SV, Aaronson PI, Ward JP - Cardiovasc. Res. (2015)

U46619 and SPC-induced contraction, and effects of Tempol and nifedipine. (A) Cumulative concentration–response curves for U46619: control (filled circle), SPC (1 µmol/L; open circle), SPC + Tempol (open square); 12 MA (6 rats). Tempol alone (filled square); n = 8 MA (4 rats). Mean pD2: control: 7.11 ± 0.02; SPC: 7.53 ± 0.03, P < 0.001 vs. control; SPC + Tempol: 6.99 ± 0.02, P < 0.001 vs. SPC, P < 0.02 vs. control; RM ANOVA, Holm-Sidak post hoc. pD2 for Tempol alone: 6.90 ± 0.08, NS vs. Tempol + SPC; P < 0.05 vs. Control; one-way ANOVA, Holm-Sidak post hoc. Bars = SEM. (B) Similar to A, but in the presence of nifedipine (3 µmol/L; open square), and SPC + nifedipine (filled square); 15 MA (9 rats). Control: pD2: 7.04 ± 0.06, Vmax: 144 ± 13% KPSS; nifedipine: pD2: 6.64 ± 0.05, P < 0.001 vs. control, Vmax: 43 ± 5% KPSS, P < 0.001 vs. control; SPC + nifedipine: pD2: 6.67 ± 0.03, NS vs. nifedipine alone, Vmax: 53 ± 6% KPSS, NS vs. nifedipine alone; RM ANOVA, Holm-Sidak post hoc. (C) Cumulative concentration–response curves for SPC in MA (filled circles); 16 MA (10 rats), with Tempol (filled squares); 8 MA (5 rats), or nifedipine (open squares); 10 MA (6 rats). SPC: pD2: 5.08 ± 0.04, Vmax: 16.8 ± 1.3% KPSS; SPC + Tempol: pD2: 4.84 ± 0.06, P < 0.02 vs. control, Vmax: 4.24 ± 1.2% KPSS, P < 0.001 vs. control; SPC + nifedipine: pD2: 5.10 ± 0.06, NS vs. control, Vmax: 8.25 ± 1.1% KPSS, P < 0.002 vs. control, P < 0.05 vs. Tempol; one-way ANOVA, Holm-Sidak post hoc. Bars = SEM (not shown if smaller than symbol).
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CVV029F4: U46619 and SPC-induced contraction, and effects of Tempol and nifedipine. (A) Cumulative concentration–response curves for U46619: control (filled circle), SPC (1 µmol/L; open circle), SPC + Tempol (open square); 12 MA (6 rats). Tempol alone (filled square); n = 8 MA (4 rats). Mean pD2: control: 7.11 ± 0.02; SPC: 7.53 ± 0.03, P < 0.001 vs. control; SPC + Tempol: 6.99 ± 0.02, P < 0.001 vs. SPC, P < 0.02 vs. control; RM ANOVA, Holm-Sidak post hoc. pD2 for Tempol alone: 6.90 ± 0.08, NS vs. Tempol + SPC; P < 0.05 vs. Control; one-way ANOVA, Holm-Sidak post hoc. Bars = SEM. (B) Similar to A, but in the presence of nifedipine (3 µmol/L; open square), and SPC + nifedipine (filled square); 15 MA (9 rats). Control: pD2: 7.04 ± 0.06, Vmax: 144 ± 13% KPSS; nifedipine: pD2: 6.64 ± 0.05, P < 0.001 vs. control, Vmax: 43 ± 5% KPSS, P < 0.001 vs. control; SPC + nifedipine: pD2: 6.67 ± 0.03, NS vs. nifedipine alone, Vmax: 53 ± 6% KPSS, NS vs. nifedipine alone; RM ANOVA, Holm-Sidak post hoc. (C) Cumulative concentration–response curves for SPC in MA (filled circles); 16 MA (10 rats), with Tempol (filled squares); 8 MA (5 rats), or nifedipine (open squares); 10 MA (6 rats). SPC: pD2: 5.08 ± 0.04, Vmax: 16.8 ± 1.3% KPSS; SPC + Tempol: pD2: 4.84 ± 0.06, P < 0.02 vs. control, Vmax: 4.24 ± 1.2% KPSS, P < 0.001 vs. control; SPC + nifedipine: pD2: 5.10 ± 0.06, NS vs. control, Vmax: 8.25 ± 1.1% KPSS, P < 0.002 vs. control, P < 0.05 vs. Tempol; one-way ANOVA, Holm-Sidak post hoc. Bars = SEM (not shown if smaller than symbol).
Mentions: We examined whether ROS were also responsible for SPC-induced potentiation of agonist-induced contraction. We utilized U46619, as unlike PGF2α it only activates TP receptors; experiments were performed in the presence of 100 µmol/L l-NAME to mitigate against any complicating effects of nitric oxide. U46619 concentration–response curves are repeatable; three were performed on each MA: control, following incubation with SPC (1 µmol/L), and SPC plus Tempol (3 mmol/L). A separate set of time-matched experiments were performed with Tempol alone. SPC caused a large leftward shift in the U46619 concentration–response relationship (P < 0.001), which was ablated in the presence of Tempol such that the relationship was shifted significantly to the right of control (P < 0.05; Figure 4A). There was no difference between the effects of SPC plus Tempol and Tempol alone.Figure 4

Bottom Line: The intracellular superoxide generator LY83583 mimicked the effect of SPC.In patch-clamped mesenteric artery cells, SPC (200 nmol/L) enhanced Ba2+ current through L-type Ca2+ channels, an action abolished by Tempol but mimicked by LY83583.Our results suggest that low concentrations of SPC activate a PLC-coupled and NOX1-mediated increase in ROS, with consequent enhancement of voltage-gated Ca2+ entry and thus vasoreactivity.

View Article: PubMed Central - PubMed

Affiliation: Division of Asthma, Allergy, and Lung Biology, King's College London, 5th Floor Tower Wing, Guy's Campus, London SE1 9RT, UK.

No MeSH data available.


Related in: MedlinePlus