Korean J Physiol Pharmacol.  2005 Aug;9(4):187-193.

Protein Kinase C Activates ATP-sensitive Potassium Channels in Rabbit Ventricular Myocytes

• Kim N
• Youm JB
• Joo H
• Kim H
• Kim E
• Han J

Abstract

Several signal transduction pathways have been implicated in ischemic preconditioning induced by the activation of ATP-sensitive K+ (KATP) channels. We examined whether protein kinase C (PKC) modulated the activity of KATP channels by recording KATP channel currents in rabbit ventricular myocytes using patch-clamp technique and found that phorbol 12, 13-didecanoate (PDD) enhanced pinacidil-induced KATP channel activity in the cell-attached configuration; and this effect was prevented by bisindolylmaleimide (BIM). KATP channel activity was not increased by 4alpha-PDD. In excised inside-out patches, PKC stimulated KATP channels in the presence of 1 mM ATP, and this effect was abolished in the presence of BIM. Heat-inactivated PKC had no effect on channel activity. PKC-induced activation of KATP channels was reversed by PP2A, and this effect was not detected in the presence of okadaic acid. These results suggest that PKC activates KATP channels in rabbit ventricular myocytes.

Keyword

KATP channel; Patch-clamp electrophysiology; Protein kinase C; Phorbol 12, 13-didecanoate; Bisindolylmaleimide

MeSH Terms

Adenosine Triphosphate
Ischemic Preconditioning
KATP Channels*
Muscle Cells*
Okadaic Acid
Patch-Clamp Techniques
Protein Kinase C*
Protein Kinases*
Signal Transduction
Adenosine Triphosphate
KATP Channels
Okadaic Acid
Protein Kinase C
Protein Kinases