What question did this study set out to answer?

The aim is to examine the role of hydrogen peroxide in altering calcium channel activity during hypoxia in cardiac cells.

October 3, 2002Circulation ResearchOpen Access

Decreasing Cellular Hydrogen Peroxide With Catalase Mimics the Effects of Hypoxia on the Sensitivity of the L-Type Ca ²⁺ Channel to β-Adrenergic Receptor Stimulation in Cardiac Myocytes

View Full Paper

Ask AI

Bookmark

Population

Guinea pig ventricular myocytes

Comparison

Dialysis with catalase or extracellularly… vs Cells dialyzed with heat-inactivated catalase or…

Design

Preclinical

Authors

LHLivia C. HoolThe University of Western Australia PAPeter G. ArthurThe University of Western Australia

Discussion

Member takes

Implication

May explain altered beta-adrenergic Ca-channel responsiveness in hypoxic myocytes; hypothesis-generating for human ischemia mechanisms.

Key Points

The aim is to examine the role of hydrogen peroxide in altering calcium channel activity during hypoxia in cardiac cells.
Guinea pig ventricular myocytes were treated with catalase to lower hydrogen peroxide levels.
Calcium currents (ICa-L) were measured during beta-adrenergic receptor stimulation with isoproterenol (Iso).
Mitochondrial function was inhibited to observe effects on hydrogen peroxide production.
Catalase decreased the K(0.5) for ICa-L activation by Iso from 2.7 nmol/L to 0.4 nmol/L.
Prior H2O2 exposure attenuated the effects of hypoxia on ICa-L sensitivity to Iso.
Hypoxia was associated with a significant reduction in hydrogen peroxide production in myocytes.

Structured PICO

Population

Guinea pig ventricular myocytes

Intervention

Dialysis with catalase (intracellular) or extracellularly applied catalase, exposure to hypoxia, H2O2, myxothiazol, or FCCP

Comparator

Cells dialyzed with heat-inactivated catalase or baseline normoxic conditions

Outcome

Sensitivity of L-type Ca2+ current (I(Ca-L)) to beta-adrenergic receptor stimulation (isoproterenol) and basal I(Ca-L) activitysurrogate

Hypoxia mediates changes in L-type Ca2+ channel activity and beta-adrenergic responsiveness in cardiac myocytes by lowering intracellular hydrogen peroxide levels.

Cite This Study

Hool et al. (2002) studied this question.

synapsesocial.com/papers/6a7405e4acfb3e7ed3eafc53 https://doi.org/10.1161/01.res.0000035528.00678.d5

View Full Paper

Ask AI

Bookmark

Decreasing Cellular Hydrogen Peroxide With Catalase Mimics the Effects of Hypoxia on the Sensitivity of the L-Type Ca ²⁺ Channel to β-Adrenergic Receptor Stimulation in Cardiac Myocytes

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Decreasing Cellular Hydrogen Peroxide With Catalase Mimics the Effects of Hypoxia on the Sensitivity of the L-Type Ca ²⁺ Channel to β-Adrenergic Receptor Stimulation in Cardiac Myocytes

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider