Hui Chen1,2,3, Yongjun Chen1,2,3, Jing Yang1,2,3, Pan Wu1,2,3, Xin Wang1,2,3, Congxin Huang4,5,6. 1. Department of Cardiology, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuchang District, 430060, Wuhan, Hubei Province, China. 2. Cardiovascular Research Institute, Wuhan University, 430060, Wuhan, China. 3. Hubei Key Laboratory of Cardiology, 430060, Wuhan, China. 4. Department of Cardiology, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuchang District, 430060, Wuhan, Hubei Province, China. huangconxin@126.com. 5. Cardiovascular Research Institute, Wuhan University, 430060, Wuhan, China. huangconxin@126.com. 6. Hubei Key Laboratory of Cardiology, 430060, Wuhan, China. huangconxin@126.com.
Abstract
BACKGROUND: In the present study, the electropharmacological activity of traditional Chinese medicine, Ginkgo biloba extract (GBE), on human hyperpolarization-activated nucleotide-gated (HCN) channels and the underlying "funny" currents was investigated. METHODS: Standard two-electrode voltage-clamp recordings were employed to examine the properties of cloned HCN subunit currents expressed in Xenopus oocytes under controlled conditions and GBE administration. RESULTS: We found that GBE irreversibly inhibited the HCN2 and HCN4 channel currents in a concentration-dependent fashion and that the HCN4 current was more sensitive to GBE compared with HCN2. In addition, GBE inhibition of the current amplitudes of HCN2 and HCN4 currents was accompanied by a decrease in the activation and deactivation kinetics. CONCLUSION: The results of this study contribute toward illustrating the antiarrhythmic mechanism of GBE, which might be useful for the treatment of arrhythmia.
BACKGROUND: In the present study, the electropharmacological activity of traditional Chinese medicine, Ginkgo biloba extract (GBE), on human hyperpolarization-activated nucleotide-gated (HCN) channels and the underlying "funny" currents was investigated. METHODS: Standard two-electrode voltage-clamp recordings were employed to examine the properties of cloned HCN subunit currents expressed in Xenopus oocytes under controlled conditions and GBE administration. RESULTS: We found that GBE irreversibly inhibited the HCN2 and HCN4 channel currents in a concentration-dependent fashion and that the HCN4 current was more sensitive to GBE compared with HCN2. In addition, GBE inhibition of the current amplitudes of HCN2 and HCN4 currents was accompanied by a decrease in the activation and deactivation kinetics. CONCLUSION: The results of this study contribute toward illustrating the antiarrhythmic mechanism of GBE, which might be useful for the treatment of arrhythmia.