Wang F, Zhao G, Cheng L, Zhou HY, Fu LY, Yao WX. Effects of berberine on potassium currents in acutely isolated CA1 pyramidal neurons of rat hippocampus.
Brain Res 2004;
999:91-7. [PMID:
14746925 DOI:
10.1016/j.brainres.2003.11.036]
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Abstract
The effects of berberine, an isoquinoline alkaloid with antiarrhythmic action, on voltage-dependent potassium currents were studied in acutely isolated CA1 pyramidal neurons of rat hippocampus by using the whole-cell patch-clamp techniques. Berberine blocked transient outward potassium current (IA) and delayed rectifier potassium current (IK) in a concentration-dependent manner with EC50 of 22.94+/-4.96 microM and 10.86+/-1.06 microM, Emax of 67.47+/-4.00% and 67.14+/-1.79%, n of 0.77+/-0.08 and 0.96+/-0.07, respectively. Berberine 30 microM shifted the steady-state activation curve and inactivation curve of IA to more negative potentials, but mainly affected the inactivation kinetics. Berberine 30 microM positively shifted the steady-state activation curve of IK. These results suggested that blockades on K+ currents by berberine are preferential for IK, and contribute to its protective action against ischemic brain damage.
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