MilliporeSigma
  • Home
  • Search Results
  • Nox1 upregulates the function of vascular T-type calcium channels following chronic nitric oxide deficit.

Nox1 upregulates the function of vascular T-type calcium channels following chronic nitric oxide deficit.

Pflugers Archiv : European journal of physiology (2014-06-14)
Lauren Howitt, Klaus I Matthaei, Grant R Drummond, Caryl E Hill
ABSTRACT

Cardiovascular disease is characterised by reduced nitric oxide bioavailability resulting from oxidative stress. Our previous studies have shown that nitric oxide deficit per se increases the contribution of T-type calcium channels to vascular tone through increased superoxide from NADPH oxidase (Nox). The aim of the present study was therefore to identify the Nox isoform responsible for modulating T-type channel function, as T-type channels are implicated in several pathophysiological conditions involving oxidative stress. We evaluated T-channel function in skeletal muscle arterioles in vivo, using a novel T-channel blocker, TTA-A2 (3 μmol/L), which demonstrated no cross reactivity with L-type channels. Wild-type and Nox2 knockout (Nox2ko) mice were treated with the nitric oxide synthase inhibitor L-NAME (40 mg/kg/day) for 2 weeks. L-NAME treatment significantly increased systolic blood pressure and the contribution of T-type calcium channels to arteriolar tone in wild-type mice, and this was not prevented by Nox2 deletion. In Nox2ko mice, pharmacological inhibition of Nox1 (10 μmol/L ML171), Nox4 (10 μmol/L VAS2870) and Nox4-derived hydrogen peroxide (500 U/mL catalase) significantly reduced the effect of chronic nitric oxide inhibition on T-type channel function. In contrast, in wild-type mice, ML171 and VAS2870, but not catalase, reduced the contribution of T-type channels to vascular tone, suggesting a role for Nox1 and non-selective actions of VAS2870. We conclude that Nox1, but not Nox2 or Nox4, is responsible for the upregulation of T-type calcium channels elicited by chronic nitric oxide deficit. These data point to an important role for this isoform in increasing T-type channel function during oxidative stress.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Hydrogen peroxide solution, contains inhibitor, 30 wt. % in H2O, meets USP testing specifications
Sigma-Aldrich
Hydrogen peroxide solution, contains inhibitor, 30 wt. % in H2O, ACS reagent
Sigma-Aldrich
Hydrogen peroxide solution, 50 wt. % in H2O, stabilized
Sigma-Aldrich
Sodium hydrogencarbonate, −40-+140 mesh, ≥95%
Sigma-Aldrich
Hydrogen peroxide solution, contains inhibitor, 35 wt. % in H2O
Sigma-Aldrich
Hydrogen peroxide solution, contains ~200 ppm acetanilide as stabilizer, 3 wt. % in H2O
Sigma-Aldrich
Hydrogen peroxide solution, purum p.a., ≥35% (RT)
Sigma-Aldrich
Sodium bicarbonate, puriss. p.a., ACS reagent, reag. Ph. Eur., ≥99.7%
Sigma-Aldrich
Sodium bicarbonate, ReagentPlus®, ≥99.5%, powder
Sigma-Aldrich
Sodium bicarbonate, puriss., meets analytical specification of Ph. Eur., BP, USP, FCC, E500, 99.0-100.5%, powder
Sigma-Aldrich
Sodium bicarbonate, anhydrous, free-flowing, Redi-Dri, ReagentPlus®, ≥99.5%
Sigma-Aldrich
Sodium bicarbonate, ACS reagent, ≥99.7%
Sigma-Aldrich
Hydrogen Peroxide Solution, 30% (w/w), puriss. p.a., reag. ISO, reag. Ph. Eur.
Sigma-Aldrich
Sodium bicarbonate, anhydrous, free-flowing, Redi-Dri, ACS reagent, ≥99.7%
Sigma-Aldrich
Sodium chloride solution, 0.85%
Sigma-Aldrich
Sodium chloride, AnhydroBeads, −10 mesh, 99.99% trace metals basis
Sigma-Aldrich
Sodium chloride, AnhydroBeads, −10 mesh, 99.999% trace metals basis
Sigma-Aldrich
Sodium chloride-35Cl, 99 atom % 35Cl
Sigma-Aldrich
Sodium chloride, random crystals, optical grade, 99.9% trace metals basis
Sigma-Aldrich
Hydrogen peroxide solution, contains potassium stannate as inhibitor, 30-32 wt. % in water, semiconductor grade, 99.999% trace metals basis
Sigma-Aldrich
Sodium chloride, 99.999% trace metals basis
Sigma-Aldrich
Hydrogen peroxide solution, tested according to Ph. Eur.
Supelco
Hydrogen peroxide solution, ≥30%, for trace analysis
Sigma-Aldrich
Hydrogen peroxide solution, 34.5-36.5%
Sigma-Aldrich
Sodium chloride solution, 0.9% in water, BioXtra, suitable for cell culture
Sigma-Aldrich
Sodium chloride, tablet
Sigma-Aldrich
Hydrogen peroxide solution, 30 % (w/w) in H2O, contains stabilizer
Sigma-Aldrich
Sodium chloride, for molecular biology, DNase, RNase, and protease, none detected, ≥99% (titration)
Sigma-Aldrich
Sodium chloride, BioXtra, ≥99.5% (AT)
Sigma-Aldrich
Sodium chloride solution, 5 M in H2O, BioReagent, for molecular biology, suitable for cell culture