What question did this study set out to answer?

To determine whether the cAMP sensor Epac directly modulates the sensitivity of ATP-sensitive potassium (KATP) channels to ATP inhibition in human pancreatic beta-cells and rat INS-1 cells.

January 18, 2008The Journal of PhysiologyOpen Access

Role of the cAMP sensor Epac as a determinant of KATP channel ATP sensitivity in human pancreatic β‐cells and rat INS‐1 cells

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Authors

GKGuoxin Kang CLColin A. Leech OCOleg G. Chepurny

Discussion

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Overview

Electrophysiological study reveals Epac activation enhances ATP-dependent inhibition of KATP channels in pancreatic beta-cells, indicating a novel regulatory mechanism for insulin release.

Key Points

To determine whether the cAMP sensor Epac directly modulates the sensitivity of ATP-sensitive potassium (KATP) channels to ATP inhibition in human pancreatic beta-cells and rat INS-1 cells.
Conducted single-channel patch-clamp recordings on excised plasma membrane patches from human beta-cells and rat insulin-secreting INS-1 cells.
Assessed KATP channel activity and ATP concentration-inhibition curves following exposure to the Epac-selective cAMP analogue 2'-O-Me-cAMP and the phosphodiesterase-resistant analogue Sp-8-pCPT-2'-O-Me-cAMPS.
Treatment with 50 µM 2'-O-Me-cAMP shifted the ATP IC50 for channel inhibition from 22 µM to 1 µM in human beta-cells and from 14 µM to 4 µM in rat INS-1 cells.
Under a fixed 10 µM ATP concentration, 2'-O-Me-cAMP inhibited channel activity in a reversible, dose-dependent manner with an IC50 of 12 µM in both cell types.
Application of Sp-8-pCPT-2'-O-Me-cAMPS similarly suppressed channel activity, demonstrating that inhibition does not result from hydrolysis into adenosine derivatives.

Cite This Study

Kang et al. (2008) studied this question.

synapsesocial.com/papers/6a7322cf02f7f7ff1dacb91d https://doi.org/10.1113/jphysiol.2007.143818

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January 18, 2008The Journal of PhysiologyOpen Access

Role of the cAMP sensor Epac as a determinant of KATP channel ATP sensitivity in human pancreatic β‐cells and rat INS‐1 cells

View Full Paper

Ask AI

Bookmark

Authors

GKGuoxin Kang CLColin A. Leech OCOleg G. Chepurny

Discussion

Member takes

Overview

Electrophysiological study reveals Epac activation enhances ATP-dependent inhibition of KATP channels in pancreatic beta-cells, indicating a novel regulatory mechanism for insulin release.

Key Points

To determine whether the cAMP sensor Epac directly modulates the sensitivity of ATP-sensitive potassium (KATP) channels to ATP inhibition in human pancreatic beta-cells and rat INS-1 cells.
Conducted single-channel patch-clamp recordings on excised plasma membrane patches from human beta-cells and rat insulin-secreting INS-1 cells.
Assessed KATP channel activity and ATP concentration-inhibition curves following exposure to the Epac-selective cAMP analogue 2'-O-Me-cAMP and the phosphodiesterase-resistant analogue Sp-8-pCPT-2'-O-Me-cAMPS.
Treatment with 50 µM 2'-O-Me-cAMP shifted the ATP IC50 for channel inhibition from 22 µM to 1 µM in human beta-cells and from 14 µM to 4 µM in rat INS-1 cells.
Under a fixed 10 µM ATP concentration, 2'-O-Me-cAMP inhibited channel activity in a reversible, dose-dependent manner with an IC50 of 12 µM in both cell types.
Application of Sp-8-pCPT-2'-O-Me-cAMPS similarly suppressed channel activity, demonstrating that inhibition does not result from hydrolysis into adenosine derivatives.

Cite This Study

Kang et al. (2008) studied this question.

synapsesocial.com/papers/6a7322cf02f7f7ff1dacb91d https://doi.org/10.1113/jphysiol.2007.143818

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