Modulation of protein kinase A and protein kinase C on the delayed rectifier potassium current in guinea pig ventricular myocytes.
- Author:
Yang LI
1
;
Li-ying FU
;
Wei-xing YAO
Author Information
- Publication Type:Journal Article
- MeSH: Animals; Cyclic AMP-Dependent Protein Kinases; pharmacology; Delayed Rectifier Potassium Channels; metabolism; Female; Guinea Pigs; Heart Ventricles; cytology; drug effects; Male; Myocytes, Cardiac; drug effects; metabolism; Patch-Clamp Techniques; Potassium; metabolism; Protein Kinase C; pharmacology
- From: Chinese Journal of Applied Physiology 2002;18(4):354-357
- CountryChina
- Language:Chinese
-
Abstract:
AIMTo study modulation of protein kinase A (PKA) and protein kinase C (PKC) on the delayed rectifier potassium current (Ik)in guinea pig ventricular myocytes.
METHODSThe delayed rectifier potassium current was recorded by using whole cell arrangement of the patch-clamp procedure.
RESULTScAMP 150 micromol/L increased intracellularly Ik and Ik,tail(pA/pF) from 13.7 +/- 2.1 and 6.1 +/- 0.1 to 18.5 +/- 3.3 and 6.4 +/- 2.1 (P < 0.01, n=6). Ik and Ik,tail(pA/pF) were augmented by 8-CPT-cAMP 150 micromol/L extracellularly from 11.4 +/- 1.8 and 5.3 +/- 0.6 to 17.9 +/- 4.0 and 6.2 +/- 1.3. The half-maximal voltage of activation of Ik was shifted from + 23.3 mV to 18.7 mV by cAMP. Phorbol 12-myristate 13-acetate(PMA, 10.0 micromol/L) applied intracellularly caused an enhance effect on Ik, with increasing Ik and Ik,tail(pA/pF) from 12.9 +/- 1.8 and 5.0 +/- 1.7 to 23.7 +/- 2.8 and 7.5 +/- 1.1. With shifting position potential of depolarization, effect of PMA on Ik was gradually augmented. PMA resulted in shifting the slop of activation curve from +15.3 mV to +25.6 mV, with only a small effect on the half-maximal voltage of activation of Ik.
CONCLUSIONIk was increased by both PKA and PKC, with different characteristics of regulation.
