@article{APS8279,
author = {Kai Huang and Gui-zhu Dai and Xin-hua Li and Qu Fan and Lan Cheng and Yi-bai Feng and Guo-jin Xia and Wei-xin Yao},
title = {Blocking L-calcium current by l-tetrahydropalmatine in single ventricular myocyte of guinea pigs.},
journal = {Acta Pharmacologica Sinica},
volume = {20},
number = {10},
year = {2016},
keywords = {},
abstract = {AIM:
To study the effect of l-tetrahydropalmatine (l-THP) on L-type calcium channel.
METHODS:
Patch clamp technique (whole cell recording) was used to record L-Ca2+ current in single cardiac myocyte.
RESULTS:
1) l-THP 1, 10, and 100 micromol.L-1 reduced ICa-max from (999 +/- 93) pA to (700 +/- 111) pA, (582 +/- 66) pA, and (420 +/- 112) pA (n = 6, P < 0.01), respectively. 2) l-THP reduced the voltage at half-maximal inactivation (V1/2) of L-Ca2+ channel to more negative potentials by 9 mV (n = 5, P < 0.05). 3) l-THP caused both tonic and use-dependent reduction of Ca2+ current. Tonic block of l-THP on Ca2+ current was 46% +/- 8% (n = 6, P < 0.01). The degree of use dependent blocking was 13.5% +/- 2.4% (n = 6, P < 0.05) at 1 Hz, the degree increased to 44% +/- 5% (n = 6, P < 0.01) at 3 Hz. 4) l-THP delayed half-recovery time of Ca2+ channel recovery from inactivity from (94 +/- 39) ms to (170 +/- 42) ms(n = 6, P < 0.01).
CONCLUSION:
l-THP has a moderate inhibitory effect on L-Ca2+ current.},
issn = {1745-7254}, url = {http://www.chinaphar.com/article/view/8279}
}