ABSTRACT
Aim To investage the regulatory effect of alizarin on renal interlobar arterial smooth muscle cells. Method The effect of alizarin on BKCa channels was observed by whole-cell patch clamp recording tech-nique. Results Selective BKCa channel blocker ibTX inhibited alizarin-induced outward current(P<0. 05);single smooth muscle cells were incubated in extracel-lular fluid with no Ca2+ 30 minutes, selective L-Ca2+channel blocker nimodipine, selective calcium ion che-lating agent BAPTA-AM and ryanodine inhibited the a-lizarin-induced BKCa channels current, too ( P <0. 05 ) . Conclusion Alizarin relaxes renales interlobar arterial smooth muscle via activation of L-Ca2+ channel firstly, which lead to Ca2+ flowed into cytoplam, and rising of Ca2+ in cytoplam ryanodine receptor indirect-ly, and BKCa is activated at last.