Effects of amiloride on potassium and calcium currents in guinea pig ventricular myocytes.
- Author:
Lan CHENG
1
;
Fang WANG
;
Hong-Yi ZHOU
;
Wei-Xing YAO
;
Guo-Jin XIA
;
Ming-Xing JIANG
Author Information
- Publication Type:Journal Article
- MeSH: Amiloride; pharmacology; Animals; Anti-Arrhythmia Agents; pharmacology; Calcium Channels, L-Type; drug effects; Calcium Channels, T-Type; drug effects; Cell Separation; Female; Guinea Pigs; Heart Ventricles; cytology; Male; Myocytes, Cardiac; drug effects; Patch-Clamp Techniques; Potassium Channels, Inwardly Rectifying; drug effects; Potassium Channels, Voltage-Gated; drug effects; Sodium-Hydrogen Exchangers; antagonists & inhibitors
- From: Acta Pharmaceutica Sinica 2004;39(7):509-513
- CountryChina
- Language:English
-
Abstract:
AIMTo elucidate the possible mechanisms underlying antiarrhythmia of the non-selective Na+/H+ exchanger inhibitor--amiloride.
METHODSSingle ventricular cells were isolated using a double-enzyme method. Effects of amiloride on voltage-dependent potassium and calcium currents in isolated guinea pig ventricular myocyte were recorded by using whole-cell patch clamp techniques.
RESULTSExposure to amiloride (10 -100 micromol x L(-1)), the L-type and T-type calcium currents were depressed. Amiloride resulted in a concentration-dependent inhibition of peak (Ca,L), But amiloride did not change the shape of their I - V curves. It only decreased the amplitudes of the currents of the two types. When myocytes were incubated with 100 micromol x L(-1) amiloride, I(Kr) was slightly depressed and I(Ks) did not change. Amiloride (1 - 100 micromol x L(-10) depressed I(K1) in a concentration-dependent manner.
CONCLUSIONAmiloride depressed potassium and calcium currents, which may give support to its uses in some diseases of the cardiovascular system.
