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Effects of Chinese herbs on multiple ion channels in isolated ventricular myocytes.
Chin Med J (Engl). 2007 Jun 20; 120(12):1068-74.CM

Abstract

BACKGROUND

Shensong Yangxin (SSYX) is one of the compound recipe of Chinese materia medica. This study was conducted to investigate the effects of SSYX on sodium current (I(Na)), L-type calcium current (I(Ca, L)), transient outward potassium current (I(to)), delayed rectifier current (I(K)), and inward rectifier potassium currents (I(K1)) in isolated ventricular myocytes.

METHODS

Whole cell patch-clamp technique was used to study ion channel currents in enzymatically isolated guinea pig or rat ventricular myocytes.

RESULTS

SSYX decreased peak I(Na) by (44.84 +/- 7.65)% from 27.21 +/- 5.35 to 14.88 +/- 2.75 pA/pF (n = 5, P < 0.05). The medicine significantly inhibited the I(Ca, L). At concentrations of 0.25, 0.50, and 1.00 g/100 ml, the peak I(Ca, L) was reduced by (19.22 +/- 1.10)%, (44.82 +/- 6.50)% and (50.69 +/- 5.64)%, respectively (n = 5, all P < 0.05). SSYX lifted the I - V curve of both I(Na) and I(Ca, L) without changing the threshold, peak and reversal potentials. At the concentration of 0.5%, the drug blocked the transient component of I(to) by 50.60% at membrane voltage of 60 mV and negatively shifted the inactive curve and delayed the recovery from channel inactivation. The tail current density of I(K) was decreased by (30.77 +/- 1.11)% (n = 5, P < 0.05) at membrane voltage of 50 mV after exposure to the medicine and the time-dependent activity of I(K) was also inhibited. Similar to the effect on I(K), the SSYX inhibited I(K1) by 33.10% at the test potential of -100 mV with little effect on reversal potential and the rectification property.

CONCLUSIONS

The experiments revealed that SSYX could block multiple ion channels such as I(Na) I(Ca, L), I(k), I(to) and I(K1), which may change the action potential duration and contribute to some of its antiarrhythmic effects.

Authors+Show Affiliations

Center for Arrhythmia Diagnosis and Treatment, Fuwai Cardiovascular Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, China.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

17637224

Citation

Li, Ning, et al. "Effects of Chinese Herbs On Multiple Ion Channels in Isolated Ventricular Myocytes." Chinese Medical Journal, vol. 120, no. 12, 2007, pp. 1068-74.
Li N, Ma KJ, Wu XF, et al. Effects of Chinese herbs on multiple ion channels in isolated ventricular myocytes. Chin Med J (Engl). 2007;120(12):1068-74.
Li, N., Ma, K. J., Wu, X. F., Sun, Q., Zhang, Y. H., & Pu, J. L. (2007). Effects of Chinese herbs on multiple ion channels in isolated ventricular myocytes. Chinese Medical Journal, 120(12), 1068-74.
Li N, et al. Effects of Chinese Herbs On Multiple Ion Channels in Isolated Ventricular Myocytes. Chin Med J (Engl). 2007 Jun 20;120(12):1068-74. PubMed PMID: 17637224.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Effects of Chinese herbs on multiple ion channels in isolated ventricular myocytes. AU - Li,Ning, AU - Ma,Ke-Juan, AU - Wu,Xiang-Feng, AU - Sun,Qi, AU - Zhang,Yi-Hui, AU - Pu,Jie-Lin, PY - 2007/7/20/pubmed PY - 2007/8/10/medline PY - 2007/7/20/entrez SP - 1068 EP - 74 JF - Chinese medical journal JO - Chin Med J (Engl) VL - 120 IS - 12 N2 - BACKGROUND: Shensong Yangxin (SSYX) is one of the compound recipe of Chinese materia medica. This study was conducted to investigate the effects of SSYX on sodium current (I(Na)), L-type calcium current (I(Ca, L)), transient outward potassium current (I(to)), delayed rectifier current (I(K)), and inward rectifier potassium currents (I(K1)) in isolated ventricular myocytes. METHODS: Whole cell patch-clamp technique was used to study ion channel currents in enzymatically isolated guinea pig or rat ventricular myocytes. RESULTS: SSYX decreased peak I(Na) by (44.84 +/- 7.65)% from 27.21 +/- 5.35 to 14.88 +/- 2.75 pA/pF (n = 5, P < 0.05). The medicine significantly inhibited the I(Ca, L). At concentrations of 0.25, 0.50, and 1.00 g/100 ml, the peak I(Ca, L) was reduced by (19.22 +/- 1.10)%, (44.82 +/- 6.50)% and (50.69 +/- 5.64)%, respectively (n = 5, all P < 0.05). SSYX lifted the I - V curve of both I(Na) and I(Ca, L) without changing the threshold, peak and reversal potentials. At the concentration of 0.5%, the drug blocked the transient component of I(to) by 50.60% at membrane voltage of 60 mV and negatively shifted the inactive curve and delayed the recovery from channel inactivation. The tail current density of I(K) was decreased by (30.77 +/- 1.11)% (n = 5, P < 0.05) at membrane voltage of 50 mV after exposure to the medicine and the time-dependent activity of I(K) was also inhibited. Similar to the effect on I(K), the SSYX inhibited I(K1) by 33.10% at the test potential of -100 mV with little effect on reversal potential and the rectification property. CONCLUSIONS: The experiments revealed that SSYX could block multiple ion channels such as I(Na) I(Ca, L), I(k), I(to) and I(K1), which may change the action potential duration and contribute to some of its antiarrhythmic effects. SN - 0366-6999 UR - https://www.unboundmedicine.com/medline/citation/17637224/Effects_of_Chinese_herbs_on_multiple_ion_channels_in_isolated_ventricular_myocytes_ L2 - https://Insights.ovid.com/pubmed?pmid=17637224 DB - PRIME DP - Unbound Medicine ER -