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Effects of benzyltetrahydropalmatine on potassium currents in guinea pig and rat ventricular myocytes.
Acta Pharmacol Sin. 2002 Jul; 23(7):612-6.AP

Abstract

AIM

To investigate the effects of benzyltetrahydropalmatine (BTHP) on rapidly activating component (I(Kr)), slowly activating component (I(Ks)) of delayed rectifier potassium current, inward rectifier potassium current (I(K1)), and transient outward potassium current (I(to)) in single ventricular myocytes.

METHODS

Whole-cell patch clamp technique was used to record ionic currents.

RESULTS

(1) BTHP 30 micromol/L reduced I(Kr) and I(Kr,tail) by 31 %+/-4 % and 36 %+/-5 % (n=6, P <0.01), respectively and inhibited I(Ks) and I(Ks,tail) by 40 %+/-6 % and 45 %+/-5 % (n=7, P <0.01), respectively. I(Kr) and I(Ks) were blocked by BTHP 1-100 micromol/L in a concentration-dependent fashion (IC50 value was 13.5 micromol/L and 95 % confidence limit: 11.2-15.8 micromol/L for I(Kr), 9.3 micromol/L and 95 % confidence limit: 7.8-11.8 micromol/L for I(Ks), respectively). (2) BTHP 5 micromol/L inhibited I(to) by 63 %+/-6 % (n=6, P <0.01). BTHP 1-100 micromol/L reduced I(to) in a concentration-dependent manner (IC50 value was 3.6 micromol/L and 95 % confidence limit: 2.9-4.3 micromol/L). (3) BTHP 200 micromol/L did not affect I(K1).

CONCLUSION

BTHP inhibited I(Kr), I(Ks), and I(to), but not I(K1). The antiarrhythmic effects of BTHP may be mainly due to its blockade on potassium channels.

Authors+Show Affiliations

Department of Cardiology, Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430030, China. liyang@hotmail.comNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

12100754

Citation

Li, Yang, et al. "Effects of Benzyltetrahydropalmatine On Potassium Currents in Guinea Pig and Rat Ventricular Myocytes." Acta Pharmacologica Sinica, vol. 23, no. 7, 2002, pp. 612-6.
Li Y, Fu LY, Yao WX, et al. Effects of benzyltetrahydropalmatine on potassium currents in guinea pig and rat ventricular myocytes. Acta Pharmacol Sin. 2002;23(7):612-6.
Li, Y., Fu, L. Y., Yao, W. X., Xia, G. J., & Jiang, M. X. (2002). Effects of benzyltetrahydropalmatine on potassium currents in guinea pig and rat ventricular myocytes. Acta Pharmacologica Sinica, 23(7), 612-6.
Li Y, et al. Effects of Benzyltetrahydropalmatine On Potassium Currents in Guinea Pig and Rat Ventricular Myocytes. Acta Pharmacol Sin. 2002;23(7):612-6. PubMed PMID: 12100754.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Effects of benzyltetrahydropalmatine on potassium currents in guinea pig and rat ventricular myocytes. AU - Li,Yang, AU - Fu,Li-Ying, AU - Yao,Wei-Xing, AU - Xia,Guo-Jin, AU - Jiang,Ming-Xing, PY - 2002/7/9/pubmed PY - 2004/8/4/medline PY - 2002/7/9/entrez SP - 612 EP - 6 JF - Acta pharmacologica Sinica JO - Acta Pharmacol Sin VL - 23 IS - 7 N2 - AIM: To investigate the effects of benzyltetrahydropalmatine (BTHP) on rapidly activating component (I(Kr)), slowly activating component (I(Ks)) of delayed rectifier potassium current, inward rectifier potassium current (I(K1)), and transient outward potassium current (I(to)) in single ventricular myocytes. METHODS: Whole-cell patch clamp technique was used to record ionic currents. RESULTS: (1) BTHP 30 micromol/L reduced I(Kr) and I(Kr,tail) by 31 %+/-4 % and 36 %+/-5 % (n=6, P <0.01), respectively and inhibited I(Ks) and I(Ks,tail) by 40 %+/-6 % and 45 %+/-5 % (n=7, P <0.01), respectively. I(Kr) and I(Ks) were blocked by BTHP 1-100 micromol/L in a concentration-dependent fashion (IC50 value was 13.5 micromol/L and 95 % confidence limit: 11.2-15.8 micromol/L for I(Kr), 9.3 micromol/L and 95 % confidence limit: 7.8-11.8 micromol/L for I(Ks), respectively). (2) BTHP 5 micromol/L inhibited I(to) by 63 %+/-6 % (n=6, P <0.01). BTHP 1-100 micromol/L reduced I(to) in a concentration-dependent manner (IC50 value was 3.6 micromol/L and 95 % confidence limit: 2.9-4.3 micromol/L). (3) BTHP 200 micromol/L did not affect I(K1). CONCLUSION: BTHP inhibited I(Kr), I(Ks), and I(to), but not I(K1). The antiarrhythmic effects of BTHP may be mainly due to its blockade on potassium channels. SN - 1671-4083 UR - https://www.unboundmedicine.com/medline/citation/12100754/Effects_of_benzyltetrahydropalmatine_on_potassium_currents_in_guinea_pig_and_rat_ventricular_myocytes_ DB - PRIME DP - Unbound Medicine ER -