S-Space College of Medicine/School of Medicine (의과대학/대학원) Dept. of Physiology (생리학교실) Journal Papers (저널논문_생리학교실)
Direct modulation of Ca(2+)-activated K(+) current by H-89 in rabbit coronary arterial smooth muscle cells
- Park, Won Sun; Son, Youn Kyoung; Kim, Nari; Youm, Jae Boum; Warda, Mohamad; Ko, Jae-Hong; Ko, Eun A; Kang, Sung Hyun; Kim, Euiyong; Earm, Yung E.; Han, Jin
- Issue Date
- Vascul Pharmacol. 2007 Feb;46(2):105-13. Epub 2006 Sep 8.
- Animals; Carbazoles/pharmacology; Coronary Circulation/drug effects; Coronary Vessels/drug effects/metabolism; Cyclic AMP/analogs & derivatives/pharmacology; Cyclic AMP-Dependent Protein Kinases/antagonists & inhibitors; Dose-Response Relationship, Drug; Enzyme Inhibitors/pharmacology; Indoles/pharmacology; Isoquinolines/*pharmacology; Membrane Potentials/drug effects; Muscle, Smooth, Vascular/*drug effects/metabolism; Okadaic Acid/pharmacology; Patch-Clamp Techniques; Phosphoprotein Phosphatases/antagonists & inhibitors; Potassium Channels, Calcium-Activated/*drug effects/metabolism; Protein Kinase Inhibitors/*pharmacology; Pyrroles/pharmacology; Rabbits; Sulfonamides/*pharmacology; Thionucleotides/pharmacology; Time Factors; Vascular Resistance/drug effects
- The effects of H-89, a potent and selective inhibitor of protein kinase A (PKA) on Ca(2+)-activated K(+) (BK(Ca)) channels in coronary arterial smooth muscle cells were examined using a patch-clamp technique. In inside-out configuration, H-89 increased the NP(o) of the BK(Ca) channel, but it reduced the dwell time of BK(Ca) currents. In whole-cell configuration, H-89 markedly increased BK(Ca) currents in a concentration-dependent manner. The EC(50) was 0.470+/-0.0741 microM based on dwell time, 0.582+/-0.0691 microM based on the NP(o), and 0.519+/-0.0295 microM based on the whole-cell current, respectively. H-85, which is an inactive form of H-89, increased BK(Ca) currents, similar to the result of H-89. The other PKA inhibitors (Rp-8-CPT-cAMPs and KT 5720) and protein phosphatase inhibitor (okadaic acid, 1 microM) had little effect on BK(Ca) currents and did not significantly alter the stimulatory effects of 1 microM H-89. These findings suggest that H-89 increases the BK(Ca) current independently of PKA.
- 1537-1891 (Print)
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