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[Emodin-induced increase in expression of β1 subunits of BKCa channel mediates relaxation of cerebral basilar artery in spontaneously hypertensive rats.] [Article in Chinese]

ZHANG Chuan-Lin, CONG Li-Na, WANG Rui, WANG Yang, MA Ke-Tao, ZHAO Lei, SI Jun-Qiang, LI Li

Electrophysiological Laboratory, Laboratory of Xinjiang Endemic and Ethnic Diseases, Shihezi University Medical College, Shihezi 832002, China

Abstract

The purposes of this study were to investigate the effect of emodin on expression of BK_Ca channel β₁ subunit in basilar artery smooth muscle cells (BASMCs) and electrophysiological characteristics of vascular smooth muscle cells in spontaneously hypertensive rats (SHR). Tail artery pressure measurement instrument was used to measure the change of SHR systolic blood pressure before and after emodin intervention. Single vascular smooth muscle cell was electrically recorded by whole-cell patch-clamp technique. Immunohistochemistry and Western blotting were used to study the distribution and expression of the BK_Ca channel β₁ subunit. The results showed that emodin decreased blood pressure of SHR from (223 ± 16) mmHg to (127 ± 12) mmHg (P < 0.01). There was no difference of blood pressure between emodin-treated SHR and Wistar rats. Emodin significantly increased outward currents of smooth muscle cells in SHR (P < 0.05), and this effect could be reversed by specific inhibitor of BK_Ca channel, IbTX. Emodin also up-regulated BK_Ca channel β₁ subunit expression in BASMCs. These results suggest that emodin relaxes cerebral basilar artery by enhancing BK_Ca current via increasing β₁ subunit expression in BASMCs.

Key words: basilar artery; smooth muscle cell; BKCa channel; emodin; Ca2+

Received: 2013-09-12　　Accepted: 2013-12-13

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Citing This Article：

ZHANG Chuan-Lin, CONG Li-Na, WANG Rui, WANG Yang, MA Ke-Tao, ZHAO Lei, SI Jun-Qiang, LI Li. [Emodin-induced increase in expression of β1 subunits of BKCa channel mediates relaxation of cerebral basilar artery in spontaneously hypertensive rats.] [Article in Chinese]. Acta Physiol Sin 2014; 66 (3): 289-294 (in Chinese with English abstract).