What does this research mean for the field?

Oxygen-derived free radicals enhance Na+/Ca2+ exchange in ventricular myocytes, which constitutes the major component of the transient inward current (ITI) generated by these radicals. Novelty: ClaimNovelty.NOVEL_FINDING. Consensus alignment: ConsensusAlignment.NEUTRAL.

What question did this study set out to answer?

To identify and characterize the transient inward current stimulated by oxygen-derived free radicals in cardiac ventricular myocytes.

September 1, 1996AJP Heart and Circulatory Physiology

Free radicals enhance Na+/Ca2+ exchange in ventricular myocytes

Q: What is the clinical evidence from this study?

Population: Cardiac reperfusion arrhythmias. Intervention: Oxygen-derived free radicals (H2O2, xanthine + xanthine oxidase). Primary outcome: Transient inward current (ITI) characterization.

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Key result

Oxygen-derived free radicals enhanced Na+/Ca2+ exchange in rabbit ventricular myocytes, identifying it as the major component of the pathological transient inward current.

Population

Patch-clamped rabbit ventricular myocytes loaded with the Ca(2+)-sensitive indicator fura 2

Design

Preclinical

Authors

JGJoshua I. GoldhaberCedars-Sinai Smidt Heart Institute

Discussion

Member takes

Implication

Supports free radical role in myocyte Ca2+ dysregulation; leaves open translation to clinical reperfusion arrhythmias.

Key Points

To identify and characterize the transient inward current stimulated by oxygen-derived free radicals in cardiac ventricular myocytes.
Recorded membrane currents in isolated rabbit ventricular myocytes using patch-clamp electrophysiology combined with fura-2 calcium fluorescence.
Challenged myocytes with brief caffeine pulses during exposure to hydrogen peroxide or xanthine plus xanthine oxidase under varied ionic conditions.
Identified sodium-calcium exchange as the primary component of the free radical-activated transient inward current based on nickel sensitivity and extracellular sodium dependence.
Showed that both hydrogen peroxide and xanthine plus xanthine oxidase similarly stimulate this inward exchange current, directly impairing myocyte relaxation.

Structured PICO

Population

Patch-clamped rabbit ventricular myocytes loaded with the Ca(2+)-sensitive indicator fura 2

Intervention

Oxygen-derived free radical (OFR) generating compounds (H2O2, xanthine + xanthine oxidase)

Outcome

Characterization of the transient inward current (ITI) and identification of its major componentsurrogate

Oxygen-derived free radicals enhance Na+/Ca2+ exchange in ventricular myocytes, providing a potential mechanism for intracellular Ca2+ overload and triggered arrhythmias during cardiac reperfusion.

Cite This Study

Joshua I. Goldhaber (1996) studied Cardiac reperfusion arrhythmias. Oxygen-derived free radicals (H2O2, xanthine + xanthine oxidase) was evaluated on Transient inward current (ITI) characterization. Oxygen-derived free radicals enhanced Na+/Ca2+ exchange in rabbit ventricular myocytes, identifying it as the major component of the pathological transient inward current.

synapsesocial.com/papers/6a0a1e0900274e073d45d9bb https://doi.org/10.1152/ajpheart.1996.271.3.h823

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Free radicals enhance Na+/Ca2+ exchange in ventricular myocytes

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Free radicals enhance Na+/Ca2+ exchange in ventricular myocytes

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider