What question did this study set out to answer?

To determine whether intracellular ATP regulates L-type Ca2+ channel currents in rat mesenteric artery smooth muscle cells through a mechanism distinct from protein phosphorylation.

February 1, 1997AJP Heart and Circulatory Physiology

Regulation of Ca2+ channel currents by intracellular ATP in smooth muscle cells of rat mesenteric artery

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Population

Vascular smooth muscle (VSM) cells isolated from rat mesenteric arteries

Comparison

Intracellularly perfused ATP vs Different concentrations of ATP and presence of…

Design

Preclinical

Authors

HYHisashi YokoshikiElectrophysiology YKY. KatsubeTokyo Medical University NSN. SperelakisTexas Tech University

Discussion

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Implication

Animal data on direct ATP modulation of vascular Ca channels leave open relevance to human disease or therapy.

Key Points

To determine whether intracellular ATP regulates L-type Ca2+ channel currents in rat mesenteric artery smooth muscle cells through a mechanism distinct from protein phosphorylation.
Conducted whole cell voltage clamp recordings combined with intracellular perfusion on vascular smooth muscle cells isolated from rat mesenteric arteries.
Measured barium currents (IBa) across varying intracellular ATP concentrations (0.1 to 5 mM) in the presence and absence of broad-spectrum kinase inhibitors (30 µM H-7 and 1 µM PKI).
Decreasing intracellular ATP from 5 to 0.1 mM decreased maximal IBa at +40 mV by 45 ± 5% (n = 8) with a dissociation constant of 0.53 mM ATP.
Increasing intracellular ATP from 0.1 to 5 mM increased maximal IBa by 57 ± 10% (n = 6), and this increase was not prevented by 30 µM H-7 or 1 µM protein kinase inhibitor.

Structured PICO

Population

Vascular smooth muscle (VSM) cells isolated from rat mesenteric arteries

Intervention

Intracellularly perfused ATP (varying concentrations, e.g., 0.1 to 5 mM)

Comparator

Different concentrations of ATP and presence of protein kinase inhibitors (30 microM H-7 or 1 microM protein kinase inhibitor)

Outcome

Ba2+ currents (I(Ba)) through Ca2+ channelssurrogate

Slow Ca2+ channels in vascular smooth muscle cells are regulated by intracellular ATP independently of phosphorylation, suggesting a direct regulatory action.

Cite This Study

Yokoshiki et al. (1997) studied this question.

synapsesocial.com/papers/6a896f3b28a30aaa563e7d17 https://doi.org/10.1152/ajpheart.1997.272.2.h814

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Regulation of Ca2+ channel currents by intracellular ATP in smooth muscle cells of rat mesenteric artery

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Regulation of Ca2+ channel currents by intracellular ATP in smooth muscle cells of rat mesenteric artery

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

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